Compilare: main.cpp: In function 'void drum(int)': main.cpp:15:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<n;++i){ ~^~ main.cpp:16:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k<=v[i+1][c]) main.cpp: In function 'int main()': main.cpp:36:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=2; i<=n; ++i) ~^~~ main.cpp:53:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<n; ++i) ~^~ main.cpp:79:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=st;i<=dr;++i) ~^~~~ main.cpp:29:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("summax.in","r",stdin); ^ main.cpp:30:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("summax.out","w",stdout); ^