Compilare: user.cpp: In function ‘int main()’: user.cpp:28:32: warning: format ‘%c’ expects argument of type ‘char*’, but argument 2 has type ‘int*’ [-Wformat=] scanf("%c%d%d",&c,&k,&p); ^ user.cpp:32:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(lin[p].size()>=k) printf("%d\n",lin[p][k-1]); ^ user.cpp:37:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(col[p].size()>=k) printf("%d\n",col[p][k-1]); ^ user.cpp:7:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qmatrix.in","r",stdin); ^ user.cpp:8:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("qmatrix.out","w",stdout); ^ user.cpp:9:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&x,&y,&q); ^ user.cpp:27:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("\n"); ^ user.cpp:28:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c%d%d",&c,&k,&p); ^ user.cpp:29:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("\n"); ^