//二分求分界点 //整数二分找右分界点 //即目标点后面的所有点满足条件 //返回值为第一个满足目标点的元素 int bsearch_1(int l,int r) { while(l<r) { int mid = l+r>>1; if(check(mid)) r=mid;//向左边找 else l =mid +1; } return l; } //整数二分找左端点 //即目标点前面的所有点满足条件 int bserch_2(int l,int r) { while(l<r) { int mid =l+r+1>>1; //加一向上取整 if(check(mid))l=mid; else r =mid-1; } return l; } //浮点数二分求右边界 double bsearch_3(double l,double r) { while(r-l>精度) { double mid =(l+r)/2; if(check(mid))r=mid; else l = mid; } return l; } //浮点数求二分求左边界 double bserch_4(double l,double r) { while(r-l>精度) { double mid =l+r+1>>1; //加一向上取整 if(check(mid))l=mid; else r =mid; } return l; }