CF607B zuma

从序列中每次消去回文串,问最少几次消除完

#include <iostream>
#include <cstring>
using namespace std ; 
 const int N=503,inf=0x3f3f3f3f;
 int f[N][N],a[N],n;
 
 signed main(){
 	int i,j,k,l,X;
 	memset(f,inf,sizeof f);
 	cin>>n;
 	for(i=1;i<=n;i++) cin>>a[i],f[i][i]=1;
 	for(i=1;i<n;i++) if(a[i]==a[i+1]) f[i][i+1]=1; else f[i][i+1]=2;
 	
 	for(l=3;l<=n;l++)
 	for(i=1;i+l-1<=n;i++){
 		j=i+l-1;
 		if(a[i]==a[j]) f[i][j]=f[i+1][j-1];
 		for(k=i;k<j;k++){
 			f[i][j]=min(f[i][j],f[i][k]+f[k+1][j]);
		 }
	 }
 	 cout<<f[1][n];
 }