POJ 1651 Multiplication Puzzle

 1 #include<set>
 2 #include<cstdio>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<iostream>
 6 #include<algorithm>
 7 using namespace std;
 8 const int N = 110;
 9 #define For(i,n) for(int i=1;i<=n;i++)
10 #define Rep(i,l,r) for(int i=l;i<=r;i++)
11 #define Down(i,r,l) for(int i=r;i>=l;i--)
12 int n,A[N];
13 long long dp[N][N];
14 
15 int main(){
16     scanf("%d",&n);
17     For(i,n) scanf("%d",&A[i]);
18     For(i,n-2) dp[i][i+2]=A[i]*A[i+2]*A[i+1];
19     Down(i,n-2,1)
20       Rep(j,i+2,n)
21         Rep(k,i+1,j-1)
22           if(dp[i][j])
23                 dp[i][j]=min(dp[i][j],dp[i][k]+dp[k][j]+A[i]*A[k]*A[j]);
24           else  dp[i][j]=dp[i][k]+dp[k][j]+A[i]*A[k]*A[j];
25     cout<<dp[1][n]<<endl;   
26     return 0;
27 }