[AcWing 778] 字符串最大跨距

#include<iostream>

using namespace std;

string s, s1, s2;
int main()
{
    char c;
    while (cin >> c, c != ',')  s += c;
    while (cin >> c, c != ',')  s1 += c;
    cin >> s2;
    if (s.size() < s1.size() || s.size() < s2.size())   puts("-1");
    else {
        int l = 0;
        while (l + s1.size() <= s.size()) {
            int k = 0;
            for ( ; k < s1.size(); k ++) {
                if (s[l + k] != s1[k])  break;
            }
            if (k == s1.size()) break;
            l ++;
        }
        int r = s.size() - s2.size();
        while (r >= 0) {
            int k = 0;
            for ( ; k < s2.size(); k ++) {
                if (s[r + k] != s2[k])  break;
            }
            if (k == s2.size()) break;
            r --;
        }
        l += s1.size() - 1;
        if (l >= r) puts("-1");
        else    printf("%d\n", r - l - 1);
    }
    return 0;
}