二分模板

从卿学姐那里偷来的模板 （整数二分  待更新更加高级的

int left = 0,ri =maxn;
int ans = -1;
while (left <= ri)
{
    int mid = (left + ri)/2;
    if( check(mid) ) ans=mid,left = mid+1;
    else ri= mid-1;
}
cout << ans <<endl;

 

这个是double 类型的二分板子

double left = 0,ri =maxn;
double ans = 0;
for(int i=0; i<100; i++)
{
    double mid = (left + ri)/2.0;
    if(check (mid))
        ans = mid, le = mid;
    else
        ri = mid;
}
cout<< ans <<endl;