Submission

Score: 100

User: august

Problemset: Red Zone

Language: cpp

Time: 0.017 second

Submitted On: 2026-03-10 20:00:56

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

const int mx = 1e5+5;

int a[mx], b[mx];

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int n,m,len,d;
    cin>> n>> m>> len>> d;

    for (int i=1; i<=n; i++) cin>> a[i];

    for (int i=1; i<=m; i++) cin>> b[i];

    int l=1, r=m; 
    while (l<=r) {
        int mid=(l+r)/2;

        vector<int> sw(mx, 0);
        for (int i=1; i<=mid; i++) sw[max(1, b[i]-len)]+=d,sw[min(n+1, b[i]+len+1)]-=d;
        for (int i=1; i<mx; i++) sw[i] += sw[i-1];

        bool ok=true;
        for (int i=1; i<=n; i++) if (a[i] > sw[i]) {
            ok=false;
            break;
        }

        if (!ok) l=mid+1;
        else r=mid-1; 
    }
    cout<< (l==m+1 ? -1 : l);
}