bank.cpp: In function 'void backtrack(int, int)':
bank.cpp:20:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
20 | for (int e = 0; e < S[i].size(); e++) {
| ~~^~~~~~~~~~~~~
bank.cpp: In function 'int main()':
bank.cpp:30:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
30 | freopen("bank.in","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
bank.cpp:31:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
31 | freopen("bank.out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~