Compilare: main.cpp: In function 'void solve(int)': main.cpp:31:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();i++){ ~^~~~~~~~~ main.cpp:35:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();i++){ ~^~~~~~~~~ main.cpp:54:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();i++){ ~^~~~~~~~~ main.cpp:58:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();i++){ ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:81:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("drum6.in","r",stdin); ^ main.cpp:82:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("drum6.out","w",stdout); ^ main.cpp:84:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&n,&m); ^ main.cpp:88:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&v[i][j]); ^