CodeForces Round #559 Div.2

A. A pile of stones

#include <bits/stdc++.h>
using namespace std;

int N;
string s;

int main() {
    scanf("%d", &N);
    cin >> s;
    int len = s.length();

    int ans = 0, temp = -1;
    for(int i = len - 1; i >= 0; i --) {
        if(s[i] == '-') {
            temp = i;
            break;
        }
    }

    if(temp == -1) ans = len;
    else {
        int minn = 1010;
        ans = 0;
        for(int i = 0; i <= temp; i ++) {
            if(s[i] == '+') ans ++;
            else ans --;
            minn = min(minn, ans);
        }

        if(minn < 0) ans = -minn;
        else ans = 0;

        for(int i = 0; i <= temp; i ++) {
            if(s[i] == '+') ans ++;
            else ans --;
        }
        ans += len - temp - 1;
    }

    printf("%d\n", ans);

    return 0;
}

B. Expansion coefficient of the array

#include <bits/stdc++.h>
using namespace std;

const int maxn = 3e5 + 10;
int N;
int a[maxn];

int main() {
    scanf("%d", &N);
    int ans = INT_MAX;
    for(int i = 1; i <= N; i ++) {
        scanf("%d", &a[i]);
        ans = min(ans, a[i] / max(i - 1, N - i));
    }

    printf("%d\n", ans);

    return 0;
}

C. The Party and Sweets

#include <bits/stdc++.h>
using namespace std;

const int maxn = 1e5 + 10;
int N, M;
long long g[maxn], b[maxn];

int main() {
    scanf("%d%d", &N, &M);
    for(int i = 1; i <= N; i ++)
        scanf("%lld", &b[i]);
    for(int i = 1; i <= M; i ++) {
        scanf("%lld", &g[i]);
    }


    sort(b + 1, b + 1 + N);
    sort(g + 1, g + 1 + M);

    if(b[N] > g[1]) printf("-1\n");
    else {
       long long ans = 0;
       for(int i = N; i >= 1; i --)
            ans += b[i] * M;
        for(int i = 2; i <= M; i ++)
            ans += g[i] - b[N];

       if(g[1] != b[N]) ans += g[1] - b[N - 1];
       printf("%lld\n", ans);
    }

    return 0;
}

D. The minimal unique substring

#include <bits/stdc++.h>
using namespace std;

int N, M;

int main() {
    scanf("%d%d", &N, &M);
    string s = "";
    if(M == 1) {
        s += '1';
        for(int i = 0; i < N - 1; i ++)
            s += '0';
    } else {
        int cnt = (N - M) / 2 + 1;
        for(int i = 0; i < N; i ++) {
            if(i % cnt == 0) s += '1';
            else s += '0';
        }
    }

    cout << s << endl;

    return 0;
}