Compilare: user.cpp: In function ‘void calc()’: user.cpp:55:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=c; i<sum.size(); i++) ^ user.cpp: In function ‘void citire()’: user.cpp:14:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&l,&c); ^ user.cpp:19:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&mat[j][i]); ^ user.cpp:26:35: 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:79:35: 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:80:37: 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); ^