题目：

题解：

bool isInterleave(char* s1, char* s2, char* s3) {
    int n = strlen(s1), m = strlen(s2), t = strlen(s3);

    int f[m + 1];
    memset(f, 0, sizeof(f));

    if (n + m != t) {
        return false;
    }

    f[0] = true;
    for (int i = 0; i <= n; ++i) {
        for (int j = 0; j <= m; ++j) {
            int p = i + j - 1;
            if (i > 0) {
                f[j] &= (s1[i - 1] == s3[p]);
            }
            if (j > 0) {
                f[j] |= (f[j - 1] && s2[j - 1] == s3[p]);
            }
        }
    }

    return f[m];
}