Codeforces Round #560 (Div. 3)

传送门

 

#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5+5;
int main() {
    int n, x, y; cin >> n >> x >> y;
    string s; cin >> s;
    reverse(s.begin(),s.end());
    int ans = 0;
    for (int i = 0; i < s.size(); ++i) {
        if (i >= x) break;
        if (i == y) {
            if (s[i] == '0') ans++;
        }
        else {
            if (s[i] == '1') ans++;
        }
    }
    cout << ans << endl;
    return 0;
}

 

#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5+5;
int a[maxn];
int main() {
    int n; cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    sort(a+1,a+1+n);
    int k = 1;
    for (int i = 1; i <= n; ++i) {
        if (a[i] >= k) k++;
    }
    cout << k-1 << endl;
    return 0;
}

 

#include <bits/stdc++.h>
using namespace std;
int main() {
    int n; cin >> n;
    string s; cin >> s;
    int len = s.size();
    string ans;
    for (int i = 0; i < len-1; i+=2) {
        if (s[i] == s[i+1]) {
            int pos = i;
            while (i < len-1 && s[pos] == s[i+1]) {
                s[i+1] = ' ';
                ++i;
            }
        }
    }
    for (int i = 0; i < len; ++i) {
        if (s[i] == ' ') continue;
        ans += s[i];
    }
    len = ans.size();
    if (ans.size() % 2 == 1) len--;
    cout << n-len << endl;
    for (int i = 0; i < len; ++i) putchar(ans[i]);
    putchar('\n');
    return 0;
}

 

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 305;
ll a[maxn];
int main() {
    int t; cin >> t;
    while (t--) {
        int n; cin >> n;
        for (int i = 1; i <= n; ++i) cin >> a[i];

        sort(a+1,a+1+n);
        ll ans = a[1]*a[n];
        bool flag = true;
        for (int i = 1; i <= n; ++i) {
            if (ans % a[i] != 0) {
                flag = false;
                break;
            }
        }
        if (flag == false) {
            cout << -1 << endl;
            continue;
        }
        ll cnt = 0; ll t = sqrt(ans);
        for (int i = 2; i <= t; ++i) {
            if (ans % i == 0) cnt++;
        }
        cnt *= 2;
        if (t*t == ans) cnt--;
        if (cnt != n) cout << -1 << endl;
        else cout << ans << endl;
    }
    return 0;
}

 

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5+5;
const int mod = 998244353;
ll a[maxn], b[maxn];
int main() {
    int n; cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = 1; i <= n; ++i) cin >> b[i];
    for (int i = 1; i <= n; ++i) a[i] = (ll)(n-i+1)*i*a[i];
    sort(a+1,a+1+n,greater<ll>() );
    sort(b+1,b+1+n,less<ll>() );
    ll ans = 0;
    for (int i = 1; i <= n; ++i) {
        ans = (ans + ((a[i]%mod) * (b[i]%mod))%mod)%mod;
    }
    cout << ans << endl;
    return 0;
}

 

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5+5;
const int inf = 0x3f3f3f3f;
struct node {
    int d, t;
}nds[maxn];
int a[maxn], b[maxn];
int n, m, sum;
bool cmp(node x, node y) {
    return x.d == y.d ? x.t < y.t : x.d < y.d;
}
bool check(int x) {
    int res = sum;
    int now = x;
    int unused = 0;
    for (int i = 0; i < n; ++i) b[i] = 0;
    int i;
    for (i = m-1; i >= 0; --i) {
        if (now >= nds[i].d) break;
    }
    for (; i >= 0; --i) {
        if (now == 0) break;
        int d = min(now,nds[i].d);
        unused += now-d;
        now = d;
        if (b[nds[i].t-1] != a[nds[i].t-1]) {
            int consump = min(d,a[nds[i].t-1]-b[nds[i].t-1]);
            res -= consump;
            b[nds[i].t-1] += consump;
            now -= consump;
        }
    }
    if (now != 0) {
        unused += now;
    }
    return res-unused/2 <= 0;
}
int main() {
    cin >> n >> m;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        sum += a[i];
    }
    for (int i = 0; i < m; ++i) {
        cin >> nds[i].d >> nds[i].t;
    }
    sort(nds,nds+m,cmp);
    int l = 1, r = inf;
    while (l <= r) {
        int mid = (l+r)/2;
        if (check(mid)) r = mid-1;
        else l = mid+1;
    }
    if (!check(r)) r++;
    cout << r << endl;
    return 0;
}

 

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5+5;
const int inf = 0x3f3f3f3f;
struct node {
    int d, t;
}nds[maxn];
int a[maxn], b[maxn];
int n, m, sum;
bool cmp(node x, node y) {
    return x.d == y.d ? x.t < y.t : x.d < y.d;
}
bool check(int x) {
    int res = sum;
    int now = x;
    int unused = 0;
    for (int i = 0; i < n; ++i) b[i] = 0;
    int i;
    for (i = m-1; i >= 0; --i) {
        if (now >= nds[i].d) break;
    }
    for (; i >= 0; --i) {
        if (now == 0) break;
        int d = min(now,nds[i].d);
        unused += now-d;
        now = d;
        if (b[nds[i].t-1] != a[nds[i].t-1]) {
            int consump = min(d,a[nds[i].t-1]-b[nds[i].t-1]);
            res -= consump;
            b[nds[i].t-1] += consump;
            now -= consump;
        }
    }
    if (now != 0) {
        unused += now;
    }
    return res-unused/2 <= 0;
}
int main() {
    cin >> n >> m;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        sum += a[i];
    }
    for (int i = 0; i < m; ++i) {
        cin >> nds[i].d >> nds[i].t;
    }
    sort(nds,nds+m,cmp);
    int l = 1, r = inf;
    while (l <= r) {
        int mid = (l+r)/2;
        if (check(mid)) r = mid-1;
        else l = mid+1;
    }
    if (!check(r)) r++;
    cout << r << endl;
    return 0;
}