Submission #871659

#	Time	Username	Problem	Language	Result	Execution time	Memory
871659		vjudge1	Difference (POI11_roz)	C++17	60 / 100	1103 ms	11716 KiB

roz

#include "bits/stdc++.h"
#define ii pair <int, int>
#define F first
#define S second
using namespace std;
const int N = 1e6+5;
int n;
char a[N];
int sum[N];
int pre[N];
vector <int> save[30];
int Get(int i, int j) {
    return sum[j] - sum[i-1];
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin >> n;
    for (int i = 1 ; i <= n ; i++) {
        cin >> a[i];
        save[a[i]-'a'].push_back(i);
    }
    int res = 0;
    for (int c1 = 0 ; c1 < 26 ; c1++)
        for (int c2 = 0 ; c2 < 26 ; c2++) {
            if (c1 == c2) continue;
            vector <ii> pos;
            pos.push_back(ii(0, 0));
            for (int i : save[c1]) pos.push_back(ii(i, 1));
            for (int i : save[c2]) pos.push_back(ii(i, -1));
            sort(pos.begin(), pos.end());
            int cur = 0;
            for (int i = 1 ; i < pos.size() ; i++) {
                int l = 1, r = i, ans = 0;
                cur += pos[i].S;
                sum[i] = sum[i-1] + (pos[i].S == -1) ;
                while(l <= r) {
                    int mid = (l + r) / 2;
                    if (Get(mid, i)) {
                        ans = mid;
                        l = mid + 1;
                    }
                    else r = mid - 1;
                }
                if (ans) res = max(res, cur-pre[ans-1]);
                pre[i] = min(cur, pre[i-1]);
            }
        }
    cout << res;
    return 0;
}

Compilation message (stderr)

roz.cpp: In function 'int main()':
roz.cpp:33:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |             for (int i = 1 ; i < pos.size() ; i++) {
      |                              ~~^~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10