http://acm.hdu.edu.cn/showproblem.php?pid=1231
求最长子段和并输出子段的端点,设置数组dp[ i ]表示以i结尾的序列的最大和。那么dp[i] = max( dp[i-1] + a[i], a[i] )。
#include <stdio.h> #include <string.h> #include <algorithm> using namespace std; int dp[10010]; int main() { int k,a[10010],f; while(~scanf("%d",&k) && k) { f = 0; for(int i = 1; i <= k; i++) { scanf("%d",&a[i]); if(a[i] >= 0) f = 1; } if(f == 0) { printf("0 %d %d\n",a[1],a[k]); continue; } int maxsum,start = 1,end = 1;//初始化 memset(dp,0,sizeof(dp)); dp[1] = a[1]; maxsum = dp[1]; for(int i = 2; i <= k; i++) { if(dp[i-1] < 0) dp[i] = a[i]; else dp[i] = dp[i-1]+a[i]; if(maxsum < dp[i]) { maxsum = dp[i]; end = i; } } int s = 0; for(int i = end; i >= 1; i--)//终点已知,根据最大和倒着找起点 { s += a[i]; if(s == maxsum) start = i; } printf("%d %d %d\n",maxsum,a[start],a[end]); } return 0; }
原文:http://blog.csdn.net/u013081425/article/details/19566859