Subtract 1 from each element
Apply window to the array for max sum of S


#include <bits/stdc++.h>
using namespace std;
#define repl(i,x,n) for(long long i=(long long)(x);i<(long long)(n);i++)
#define rep(i,x,n) for(long i=long(x);i<long(n);i++)
int main()
{
    //ifstream cin("input.in");
    //ofstream cout("output.out");
    ios::sync_with_stdio(0);cin.tie(0);
    long n,s,a[100009],p=0;
    cin>>n>>s;
    bool flag=1;
    rep(i,0,n)
    {
        cin>>a[i];
        a[i]--;
    }
    rep(i,0,n)
    {
        p+=a[i];
        if(p>s)
            flag=0;
        p=max(p,0l);
    }
    if(flag)
        cout<<"YES";
    else
        cout<<"NO";
}

Edited by author 11.12.2017 08:23