题解 | BFS

#include <complex>
#include <iostream>
using namespace std;

int main() {
    int idx1, idx2;
    string str;
    cin >> str;
    string lower_str = str;
    for (auto& c : lower_str) {
    c = tolower(c);
}
    
    int pos = lower_str.find("bob");
    cout << pos;
}
// 64 位输出请用 printf("%lld")