acm常用模板

				//求最大子段和,复杂度O(n)
				//传入串长n和内容list[]
				//返回最大子段和,重载返回子段位置(maxsum=list[start]+...+list[end])
				//可更改元素类型
				typedef int elem_t;
				
				elem_t maxsum(int n,elem_t* list){
					elem_t ret,sum=0;
					int i;
					for (ret=list[i=0];i						sum=(sum>0?sum:0)+list[i],ret=(sum>ret?sum:ret);
					return ret;
				}
				
				elem_t maxsum(int n,elem_t* list,int& start,int& end){
					elem_t ret,sum=0;
					int s,i;
					for (ret=list[start=end=s=i=0];i0?s:i))
						if ((sum=(sum>0?sum:0)+list[i])>ret)
							ret=sum,start=s,end=i;
					return ret;
				}