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MacesutedMacesuted
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Petrozavodsk Summer 2023. Day 3. ABalobanov Contest 1
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‎QOJ/9325.cpp‎

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/**
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* @file 9325.cpp
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* @author Macesuted (i@macesuted.moe)
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* @date 2025-10-31
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*
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* @copyright Copyright (c) 2025
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*
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*/
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#include <bits/stdc++.h>
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using namespace std;
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#define endl '\n'
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#define maxn 200005
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#define maxlgn 20
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#define mod 998244353
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class STList {
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private:
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int a[maxlgn][maxn], lg[maxn];
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public:
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void build(int n, int v[]) {
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for (int i = 2; i <= n; i++) lg[i] = lg[i >> 1] + 1;
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for (int i = 1; i <= n; i++) a[0][i] = v[i];
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for (int t = 1; t <= lg[n]; t++)
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for (int l = 1; l + (1 << t) - 1 <= n; l++) a[t][l] = min(a[t - 1][l], a[t - 1][l + (1 << (t - 1))]);
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return;
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}
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int query(int l, int r) {
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int t = lg[r - l + 1];
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return min(a[t][l], a[t][r - (1 << t) + 1]);
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}
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} STL;
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int a[maxn], p[maxn];
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vector<int> fl[maxn], gl[maxn], fr[maxn], gr[maxn];
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int Mod(int x) { return x >= mod ? x - mod : x; }
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void solve(int l, int r) {
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if (l > r) return;
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int x = p[STL.query(l, r)];
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solve(l, x - 1), solve(x + 1, r);
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fl[x].resize(x - l + 1), fr[x].resize(r - x + 1);
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for (int i = l; i < x; i++) {
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int y = p[STL.query(i, x - 1)];
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fl[x][x - i] = Mod(gl[y][y - i] + gr[y][x - 1 - y] + 1);
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}
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for (int i = x + 1; i <= r; i++) {
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int y = p[STL.query(x + 1, i)];
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fr[x][i - x] = Mod(gl[y][y - x - 1] + gr[y][i - y] + 1);
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}
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gl[x] = fl[x];
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for (size_t i = 1; i < gl[x].size(); i++) gl[x][i] = Mod(gl[x][i] + gl[x][i - 1]);
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gr[x] = fr[x];
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for (size_t i = 1; i < gr[x].size(); i++) gr[x][i] = Mod(gr[x][i] + gr[x][i - 1]);
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return;
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}
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void solve(void) {
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int n;
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cin >> n;
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for (int i = 1; i <= n; i++) cin >> a[i], p[a[i]] = i;
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STL.build(n, a);
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for (int i = 1; i <= n; i++) fl[i] = gl[i] = fr[i] = gr[i] = vector<int>();
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solve(1, n);
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int x = p[STL.query(1, n)];
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cout << Mod(gl[x][x - 1] + gr[x][n - x] + 1) << endl;
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return;
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}
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int main() {
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ios::sync_with_stdio(false), cin.tie(nullptr);
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int _ = 1;
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cin >> _;
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while (_--) solve();
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return 0;
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}

‎QOJ/9326.cpp‎

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/**
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* @file 9326.cpp
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* @author Macesuted (i@macesuted.moe)
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* @date 2025-10-31
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*
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* @copyright Copyright (c) 2025
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*
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*/
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#include <bits/stdc++.h>
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using namespace std;
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#define endl '\n'
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#define maxn 300005
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#define maxlgn 20
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class STList {
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private:
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int64_t a[maxlgn][maxn];
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int lg[maxn], n;
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public:
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void build(int _n) {
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n = _n;
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for (int i = 2; i <= n; i++) lg[i] = lg[i >> 1] + 1;
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return;
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}
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void modi(int p, int64_t v) {
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a[0][p] = v;
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for (int t = 1; p + (1 << t) - 1 <= n; t++) a[t][p] = min(a[t - 1][p], a[t - 1][p + (1 << (t - 1))]);
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return;
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}
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int64_t query(int l, int r) {
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int t = lg[r - l + 1];
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return min(a[t][l], a[t][r - (1 << t) + 1]);
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}
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} STLg, STLf;
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int64_t f[maxn], a[maxn];
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int ql[maxn], qr[maxn];
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void solve(void) {
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int n, c;
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cin >> n >> c;
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for (int i = 1; i <= n; i++) cin >> ql[i];
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for (int i = 1; i <= n; i++) cin >> qr[i];
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for (int i = 1; i <= n; i++) cin >> a[i];
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STLf.build(n), STLg.build(n);
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for (int i = n; i; i--) {
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if (i + ql[i] <= n) {
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f[i] = STLf.query(max(i + 1, i + ql[i] - c), i + ql[i]);
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if (i + qr[i] > n) qr[i] = n - i, f[i] = max(f[i], (int64_t)0);
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if (qr[i] > c) f[i] = max(f[i], -STLg.query(i + max(ql[i], c + 1), i + qr[i]));
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} else
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f[i] = 0;
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STLf.modi(i, f[i] += a[i]);
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if (i + c <= n) STLg.modi(i + c, -STLf.query(i, i + c));
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}
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cout << f[1] - a[1] << endl;
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return;
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}
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int main() {
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ios::sync_with_stdio(false), cin.tie(nullptr);
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int _ = 1;
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cin >> _;
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while (_--) solve();
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return 0;
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}

‎QOJ/9327.cpp‎

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/**
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* @file 9327.cpp
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* @author Macesuted (i@macesuted.moe)
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* @date 2025-10-31
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*
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* @copyright Copyright (c) 2025
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*
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*/
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#include <bits/stdc++.h>
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using namespace std;
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#define endl '\n'
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#define maxn 100005
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int a[maxn], p[maxn], sum[maxn], cnt[maxn];
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map<int, int> S;
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void solve(void) {
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int n, q;
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cin >> n >> q;
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int B = sqrt(n);
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for (int i = 1; i <= n; i++) cin >> a[i], p[a[i]] = i;
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auto add = [&](int x, int y, int delt) -> void {
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int64_t v = abs(x - y) * abs(a[x] - a[y]);
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if (v > maxn) return;
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sum[v / B] += delt, cnt[v] += delt;
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return;
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};
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auto getAns = [&](void) -> int {
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int ans = 0;
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while (!sum[ans / B]) ans += B;
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while (!cnt[ans]) ans++;
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return ans;
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};
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for (int i = 1; i <= n; i++)
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for (int j = i + 1; j <= min(n, i + B); j++) add(i, j, +1), add(p[i], p[j], +1);
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cout << getAns() << endl;
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while (q--) {
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int x, y;
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cin >> x >> y;
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auto calc = [&](int delt) -> void {
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for (int i = max(1, x - B); i <= min(n, x + B); i++)
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if (i != x) add(x, i, delt);
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for (int i = max(1, y - B); i <= min(n, y + B); i++)
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if (i != x && i != y) add(y, i, delt);
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for (int i = max(1, a[x] - B); i <= min(n, a[x] + B); i++)
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if (i != a[x]) add(x, p[i], delt);
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for (int i = max(1, a[y] - B); i <= min(n, a[y] + B); i++)
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if (i != a[x] && i != a[y]) add(y, p[i], delt);
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return;
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};
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calc(-1);
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swap(a[x], a[y]);
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swap(p[a[x]], p[a[y]]);
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calc(+1);
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cout << getAns() << endl;
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}
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return;
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}
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int main() {
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ios::sync_with_stdio(false), cin.tie(nullptr);
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int _ = 1;
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while (_--) solve();
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return 0;
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}

‎QOJ/9328.cpp‎

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/**
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* @file 9328.cpp
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* @author Macesuted (i@macesuted.moe)
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* @date 2025-10-31
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*
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* @copyright Copyright (c) 2025
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*
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*/
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#include <bits/stdc++.h>
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using namespace std;
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#define endl '\n'
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bool solve(void) {
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int n;
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string s;
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cin >> n >> s;
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vector<vector<int>> cnt(2, vector<int>(26, 0));
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for (int i = 0; i < n; i++) cnt[i & 1][s[i] - 'a']++;
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if (n & 1) {
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int cc[2] = {0, 0};
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for (int t = 0; t < 2; t++)
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for (int i = 0; i < 26; i++) cc[t] += cnt[t][i] & 1;
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int x = n >> 1 & 1;
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return cc[!x] == 0 && cc[x] == 1;
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}
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for (int i = 0; i < 26; i++)
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if (cnt[0][i] != cnt[1][i]) return false;
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return true;
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}
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int main() {
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ios::sync_with_stdio(false), cin.tie(nullptr);
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int _ = 1;
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cin >> _;
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while (_--) cout << (solve() ? "YES" : "NO") << endl;
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return 0;
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}

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