【HDOJ】1726 God’s cutter

简单DP。

/* 1726 */
#include <cstdio>
#include <cstring>
#include <cstdlib>

#define MAXN 105
#define INF 99999

bool isValid[MAXN][MAXN];
char s[MAXN];
int dp[MAXN];

bool check(int l, int r) {
    int i, j;

    for (i=l, j=r; i<=j; ++i, --j)
        if (s[i] != s[j])
            return false;
    return true;
}

int min(int a, int b) {
    return a<b ? a:b;
}

int main() {
    int len;
    int i, j, k;

    #ifndef ONLINE_JUDGE
        freopen("data.in", "r", stdin);
    #endif

    while (scanf("%s", s+1) != EOF) {
        len = strlen(s+1);
        memset(isValid, false, sizeof(isValid));
        for (i=1; i<=len; ++i) {
            isValid[i][i] = true;
            for (j=i+1; j<=len; ++j)
                isValid[i][j] = check(i, j);
        }

        dp[0] = -1;
        for (i=1; i<=len; ++i) {
            dp[i] = dp[i-1] + 1;
            for (j=1; j<i; ++j) {
                if (isValid[j][i] && dp[j-1]+1<dp[i]) {
                    dp[i] = dp[j-1] + 1;
                }
            }
        }
        printf("%d
", dp[len]);
    }

    return 0;
}