Treats for the Cows 记忆化搜索
#include<stdio.h> #include<string.h> int hash[2005][2005]; int treat[2005]; int num; int dfs(int head,int tail,int n); int main() { int i,k; while(scanf("%d",&num)!=EOF) { memset(hash,0,sizeof(hash)); for(i=0;i<num;i++) scanf("%d",&treat[i]); k=dfs(0,num-1,1); printf("%d\n",k); } return 0; } int dfs(int head,int tail,int n) { int max=0,k1,k2; if(n>num) return 0; if(hash[head][tail]) return hash[head][tail]; k1=n*treat[head]+dfs(head+1,tail,n+1); k2=n*treat[tail]+dfs(head,tail-1,n+1); max=k1>=k2?k1:k2; hash[head][tail]=max; return max; }
DP我不会,我只会DFS+记忆化来剪枝。。。。。