AC日记——Sagheer and Nubian Market codeforces 812c

C - Sagheer and Nubian Market

思路：

　　二分；

代码：

#include <bits/stdc++.h>

using namespace std;

#define maxn 1000005
#define ll long long

ll n,s,ai[maxn],ci[maxn];

inline void in(ll &now)
{
    char Cget=getchar();now=;
    while(Cget>''||Cget<'') Cget=getchar();
    while(Cget>=''&&Cget<='') now=now*+Cget-'',Cget=getchar();
}

int main()
{
    in(n),in(s);for(ll i=;i<=n;i++) in(ai[i]);
    ll l=,r=n,ans=,ans_=,mid,pos;
    for(;l<=r;)
    {
        mid=l+r>>;pos=;
        for(ll i=;i<=n;i++) ci[i]=ai[i]+i*mid;
        sort(ci+,ci+n+);for(ll i=;i<=mid;i++) pos+=ci[i];
        if(pos<=s) ans=mid,ans_=pos,l=mid+;
        else r=mid-;
    }
    printf("%lld %lld\n",ans,ans_);
    return ;
}