bzoj 1816

不看题解绝对想不出二分答案。。。。

#include<bits/stdc++.h>
#define inc(i,l,r) for(i=l;i<=r;i++)
#define dec(i,l,r) for(i=l;i>=r;i--)
#define inf 1e9
#define mem(a) memset(a,0,sizeof(a))
#define ll long long
#define NM 55
using namespace std;
int read(){
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
    return x*f;
}
int a[NM],n,m,i,l,r,s;
int check(int x){
    int i,t=min(x,m);
    inc(i,1,n)
    if(a[i]<x){
        t-=x-a[i];
        if(t<0)return false;
    }
    return true;
}
int main(){
    n=read();m=read();
    inc(i,1,n)a[i]=read();
    l=0;r=inf;
    while(l<=r){
        int t=l+r>>1;
        if(!check(t))r=t-1;
        else l=t+1,s=t;
    }
    printf("%d",s);
    return 0;
}