Submission #1002300

#	Time	Username	Problem	Language	Result	Execution time	Memory
1002300		votranngocvy	Difference (POI11_roz)	C++14	100 / 100	627 ms	18260 KiB

roz

#include <bits/stdc++.h>
using namespace std;
 
#define NAME "task"
const int N = 1e6 + 5;
const int inf = 0x3f3f3f3f;
vector<int>pos[30];
int n,ans,Min[N];
char s[N];
 
void calc(int a,int b) {
    vector<int>vec;
    int i = 0,j = 0;
    while (i < (int)pos[a].size() && j < (int)pos[b].size()) {
        if (pos[a][i] < pos[b][j]) {
            vec.push_back(1);
            i++;
        }
        else {
            vec.push_back(-1);
            j++;
        }
    }
    while (i < (int)pos[a].size()) {
        vec.push_back(1);
        i++;
    }
    while (j < (int)pos[b].size()) {
        vec.push_back(-1);
        j++;
    }
    int m = (int)vec.size();
    Min[0] = 0;
    int sum = 0; int last = -1;
    for (int i = 1; i <= m; i++) {
        if (vec[i - 1] == -1) last = i - 1;
        sum += vec[i - 1];
        if (last != -1) ans = max(ans,sum - Min[last]);
        Min[i] = min(Min[i - 1],sum);
    }
}
 
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen(NAME".inp","r",stdin);
    //freopen(NAME".out","w",stdout);
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> s[i];
        pos[s[i] - 'a'].push_back(i);
    }
    for (int i = 0; i < 26; i++)
        for (int j = 0; j < 26; j++) 
            if (i != j && pos[i].size() && pos[j].size()) calc(i,j);
    cout << ans << "\n";
}

• 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: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10