很经典的入门dp
/*******************************************************************************/ /* OS : 3.2.0-58-generic #88-Ubuntu SMP Tue Dec 3 UTC 2013 GNU/Linux * Compiler : g++ (GCC) 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) * Encoding : UTF8 * Date : 2014-03-23 * All Rights Reserved by yaolong. *****************************************************************************/ /* Description: *************************************************************** *****************************************************************************/ /* Analysis: ****************************************************************** *****************************************************************************/ /*****************************************************************************/ #include<iostream> #include<cstdio> #include<cstring> using namespace std; #define INF 1<<30 #define MAX 100 int m[MAX][MAX],s[MAX][MAX],p[MAX]; void MatrixChain(int n){ int i,j,l,q,k; for(i=1;i<=n;i++) m[i][i]=0; //自己乘自己 for(l=2;l<=n;l++) for(i=1;i<=n-l+1;i++){ j=i+l-1; m[i][j]=INF; for(k=i;k<=j-1;k++){ q=m[i][k]+m[k+1][j]+p[i-1]*p[k]*p[j]; if(q<m[i][j]){ m[i][j]=q; s[i][j]=k; } } } } void trace_back(int i,int j){ if(i==j) {cout<<"A"<<i; return;} cout<<"("; trace_back(i,s[i][j]); cout<<" x "; trace_back(s[i][j]+1,j); cout<<")"; } int main(){ #ifndef ONLINE_JUDGE freopen("in.txt","r",stdin); #endif int i,n,cases=1; while(cin>>n&&n){ for(i=1;i<=n;i++){ cin>>p[i-1]>>p[i]; } cout<<"Case "<<cases++<<": "; MatrixChain(n); trace_back(1,n); cout<<endl; } #ifndef ONLINE_JUDGE fclose(stdin); #endif return 0; }
其实我觉得题目输入冗余太高了……完全没必要。。。。wa了一次,因为没有写case x: ..