Maximum sum
|code--------------------------------------------------------------------------------------------------+
|001| /***************************************************************\
|002| *Author: 小呼
|003| *Created Time: Tue 06 Jul 2010 02:49:20 PM CST
|004| *File Name: a.cpp
|005| *Description:动态规划。Max_L[i]表示A[1...i]中最大的连续和，同理
|006| *Max_R[i]是指A[i...n]中最大的连续和
|007| \***************************************************************/
|008| //*====================*Head File*====================*\\
|009|
|010| #include<iostream>
|011| #include<stdio.h>
|012| #include<stdlib.h>
|013| #include<string.h>
|014| /*----------------------*Global Variable*----------------------*/
|015|
|016| //*===================*Main Program*===================*//
|017| using namespace std;
|018| int A[50001],n,Max_L[50001],Max_R[50001];
|019| int main(){
|020| . int T;
|021| . scanf("%d",&T);
|022| . while(T--){
|023| . . scanf("%d",&n);
|024| . . for(int i=1;i<=n;++i)
|025| . . scanf("%d",A+i);
|026| . . int _max=-9999999,temp=-9999999;
|027| . . for(int i=1;i<n;++i){
|028| . . . if(temp>=0)
|029| . . . temp+=A[i];
|030| . . . else
|031| . . . . temp=A[i];
|032| . . . _max=_max>temp?_max:temp;
|033| . . . Max_L[i]=_max;
|034| . . }
|035| . . _max=temp=-999999;
|036| . . for(int i=n;i>1;--i){
|037| . . . if(temp>0)
|038| . . . temp+=A[i];
|039| . . . else
|040| . . . temp=A[i];
|041| . . . _max=_max>temp?_max:temp;
|042| . . . Max_R[i]=_max;
|043| . . }
|044| . . int res=-999999;
|045| . . for(int i=1;i<n;++i){
|046| . . . res=(res>Max_L[i]+Max_R[i+1]?res:Max_L[i]+Max_R[i+1]);
|047| . . }
|048| . . printf("%d\n",res);
|049| . }
|050| . return 0;
|051| }
end+--------------------------------------------------------------------------------------------------+