DT2131

//点集A[] bool comp2(Node a,Node b){//极角排序，逆时针 int temp=cross(A[0],a,b);//叉积求极角大小 if(temp==0) return dis(A[0],a)<dis(A[0],b); return temp>0; } void graham(int n)//graham法(nlogn) { point[

POJ 1113 C - Wall Time Limit:1000MS     Memory Limit:10000KB     64bit IO Format:%lld & %llu  POJ 1113 Description Once upon a time there was a greedy King who ordered his chi

资料来源： http://blog.youkuaiyun.com/bone_ace/article/details/46239187 http://kevinew.blog.sohu.com/14735858.html 前言： 首先，什么是凸包？  假设平面上有p0~p12共13个点，过某些点作一个多边形，使这个多边形能把所有点都“包”起来。当这个多边形是凸多边形