Compilare: user.cpp: In function ‘int main()’: user.cpp:30:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<b[i].h.size(); ++j) ^ user.cpp:32:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<c.size(); ++j){ ^ user.cpp:34:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=j+1; k<c.size(); ++k)if(b[i].h[j].a[c[k]-'a'+1]==-1)b[i].h[j].a[c[k]-'a'+1]=k; ^ user.cpp:22:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("search.out", "w", stdout); ^