CF812C Sagheer and Nubian Market 二分+贪心

模拟赛给他们出T1好了~

code:

#include <bits/stdc++.h>
#define ll long long
#define N 100006
#define setIO(s) freopen(s".in","r",stdin)
using namespace std;
int n;
ll a[N],ck,A[N],S;
int check(int tmp)
{
    int i,cnt=0;
    for(i=1;i<=n;++i) A[i]=a[i]+1ll*tmp*i;
    sort(A+1,A+1+n);
    ll pp=0;
    for(i=1;i<=n;++i)
    {
        if(pp+A[i]>S) break;
        else
        {
            pp+=A[i];
            ++cnt;
            if(cnt==tmp) break;
        }
    }
    if(cnt>=tmp)
    {
        ck=pp;
        return 1;
    }
    return 0;
}
int main()
{
    int i,j;
    // setIO("input");
    scanf("%d%lld",&n,&S);
    for(i=1;i<=n;++i) scanf("%lld",&a[i]);
    int l=1,r=n,mid,ans=0;
    for(;l<=r;)
    {
        mid=(l+r)>>1;
        if(check(mid)) ans=mid,l=mid+1;
        else r=mid-1;
    }
    printf("%d %lld\n",ans,ck);
    return 0;
}