Compilare: user.cpp: In function ‘void calculareSuma()’: user.cpp:55:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sol.size() != r) ^ user.cpp:65:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); i++) ^ user.cpp: In function ‘void backtracking()’: user.cpp:121:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sol.size() != r) ^ user.cpp: In function ‘void citire()’: user.cpp:19:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &n, &m, &r, &c); ^ user.cpp:27:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &mat[i][j]); ^ user.cpp: In function ‘int main()’: user.cpp:134:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("elimin.in", "r", stdin); ^ user.cpp:135:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("elimin.out", "w", stdout); ^