Compilare: main.cpp: In function 'int main()': main.cpp:31:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<a.size();i++) ~^~~~~~~~~ main.cpp:39:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<b.size()) ~^~~~~~~~~ main.cpp:49:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==a.size()) sol.pb(j-a.size()); ~^~~~~~~~~~ main.cpp:25:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in","r",stdin); ^ main.cpp:26:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out","w",stdout); ^