Compilare: user.cpp: In function ‘long long int doing(int, int)’: user.cpp:22:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (t=0;t<r[i][j].size();t++) { ^ user.cpp: In function ‘int main()’: user.cpp:37:40: warning: format ‘%s’ expects argument of type ‘char*’, but argument 4 has type ‘char (*)[260]’ [-Wformat=] scanf("%d %d %s",&l[t],&c[t],&s); ^ user.cpp:32:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.in","r",stdin); ^ user.cpp:33:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mxl.out","w",stdout); ^ user.cpp:34:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&k); ^ user.cpp:37:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %s",&l[t],&c[t],&s); ^