Compilare: main.cpp: In function 'int main()': main.cpp:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(auto i=0;i<n;){ ~^~ main.cpp:30:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(auto i =0;i<m;++i){ ~^~ main.cpp:36:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j == n-1) { ~~^~~~~~ main.cpp:11:37: 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:12:39: 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); ^