AC日记——砍树 codevs 1388

#include <cstdio>

using namespace std;

int n,m,maxn,minn=0x7fffffff,ai[1000001],ans=0;

long long int now;

char Cget;

inline int max(int some1,int some2)
{
    if(some1>some2) return some1;
    else return some2;
}

inline int min(int some1,int some2)
{
    if(some1<some2) return some1;
    else return some2;
}

inline bool check(int now_)
{
    now=0;
    for(int i=1;i<=n;i++)
    {
        now+=max(0,ai[i]-now_);
    }
    if(now>=m)
    {
        ans=now_;
        return true;
    }
    else return false;
}

inline void read_int(int &now_)
{
    now_=0,Cget=getchar();
    while(Cget>‘9‘||Cget<‘0‘) Cget=getchar();
    while(Cget<=‘9‘&&Cget>=‘0‘)
    {
        now_=now_*10+Cget-‘0‘;
        Cget=getchar();
    }
}

int main()
{
    //scanf("%d%d",&n,&m);
    read_int(n),read_int(m);
    for(int i=1;i<=n;i++)
    {
        //scanf("%d",&ai[i]);
        read_int(ai[i]);
        maxn=max(maxn,ai[i]);
        minn=min(minn,ai[i]);
    }
    int mid;
    while(minn<=maxn)
    {
        mid=(minn+maxn)>>1;
        if(check(mid)) minn=mid+1;
        else maxn=mid-1;
    }
    printf("%d\n",ans);
    return 0;
}