Compilare: main.cpp: In function 'void zet()': main.cpp:26:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i=1;i<s.size();i++ ) ~^~~~~~~~~ main.cpp:38:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i+z[i]<s.size() && s[z[i]]==s[i+z[i]] ) ~~~~~~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:63:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i=1;i<s.size();i++ ) ~^~~~~~~~~ main.cpp:48:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen( "prefix.in", "r", stdin ); ^ main.cpp:49:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen( "prefix.out", "w", stdout ); ^