题解 | BFS

#include <iostream>
using namespace std;

int main() {
    string s;
    cin >> s;
    int len = s.size();
    int y = -1;
    string z = "";
    for (int i = 0; i < len - 2; i++)
    {
        z = s.substr(i, 3);
        if (z == "BOB" || z == "BOb" || z == "BoB" || z == "Bob" || z == "bOB" || z == "bOb" || z == "boB" || z == "bob")
        {
            y = i;
            break;
        }
    }
    cout << y;
    return 0;
}
// 64 位输出请用 printf("%lld")