#include <stdio.h>

int N;
char S[5002];
short f[2][5001];

int main()
{
	scanf("%d%s", &N, S+1);

	int i, j, current = 0;
	for (i = 1; i <= N; ++i){
		for (j = i; j <= N; ++j){
			if (S[i] == S[N + 1 - j])
				f[current][j] = f[!current][j - 1] + 1;
			else { 
				f[current][j] = f[current][j - 1];				
				if (f[current][j] < f[!current][j])
					f[current][j] = f[!current][j];
			}
		}
		current = !current;
	}
	printf("%d", N - f[!current][N]);

	return 0;
}

• 原来改成这样就可以了 for(j =1;.......) (484) Issue 2005-12-03 04:30:04