Compilare: user.cpp: In function ‘int main()’: user.cpp:64:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[c].push_back(p); ^ user.cpp:74:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < A[0].size(); i++) ^ user.cpp:79:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < A[1].size(); i++) ^ user.cpp:43:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inputFile.c_str(), "r", stdin); ^ user.cpp:44:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outputFile.c_str(), "w", stdout); ^ user.cpp:47:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:50:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x[i], &y[i]); ^ user.cpp:51:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf(" %c", &c); ^