二分穷举寻找正好吃完的那天，因为那天后被吃完，那天没被吃完，所以用二分搜索
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; typedef long long int ll; ll m,n; int main() { scanf("%lld%lld",&n,&m); if(m>=n) printf("%lld\n",n); else { ll cnt=n-m; ll l=1,r=3e9+7; while(l<=r) { ll mid=(l+r)/2; if((mid+1)*mid/2>=cnt)//神奇的递加数列求和公式 r=mid-1; else l=mid+1; } ll day=m+l; printf("%lld\n",day); } return 0; }
转载于:https://www.cnblogs.com/Wangwanxiang/p/6696755.html
