> #include "stdio.h"
>         char str[5002];
> 	int length;
> 	short f[5002][5002];
> 	
> 	void dp() {
> 		int i,j;
> 		for(i = length - 2; i >= 0; i--) {
> 			for(j = i + 1; j < length; j++) {
> 				if(str[i] == str[j]){
> 					f[i][j] = f[i+1][j-1];
> 				} else {
> 					if(f[i+1][j] < f[i][j-1])
> 						f[i][j] = f[i+1][j] + 1;
> 					else
> 						f[i][j] = f[i][j-1] + 1;
> 				}
> 			}
> 		}
> 	}
> 	
> 	int main() {
> 		scanf("%d",&length);
> 		scanf("%s",str);
> 		dp();
> 		printf(f[0][length-1]);
>                 return 0;
> 	}


同样一段代码，用C++提交结果为什么就对了？？？
#include <iostream>
using namespace std;
        char str[5002];
	int length;
	short f[5002][5002];
	
	void dp() {
		int i,j;
		for(i = length - 2; i >= 0; i--) {
			for(j = i + 1; j < length; j++) {
				if(str[i] == str[j]){
					f[i][j] = f[i+1][j-1];
				} else {
					if(f[i+1][j] < f[i][j-1])
						f[i][j] = f[i+1][j] + 1;
					else
						f[i][j] = f[i][j-1] + 1;
				}
			}
		}
	}
	
	int main() {
		cin>>length;
		cin>>str;
		dp();
		cout<<(f[0][length-1])<<endl;
                return 0;
	}