Compilare: main.cpp: In function 'void add_hash(int)': main.cpp:14:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i < myhash[code].size() && x != myhash[code][i].first ) ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:16:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( i == myhash[code].size() ){ ~~^~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void erase_hash(int)': main.cpp:26:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i < myhash[code].size() && x != myhash[code][i].first ) ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:28:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( i < myhash[code].size() ){ ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'bool search_hash(int)': main.cpp:39:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i < myhash[code].size() && x != myhash[code][i].first ) ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:41:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return i < myhash[code].size(); ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:71:38: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d%d%d", &n, &l, &u ); ^ main.cpp:73:31: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &v[i] ); ^