Compilare: main.cpp: In function 'void pop(int)': main.cpp:20:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( i*2 + 1 >= H.size()) ~~~~~~~~^~~~~~~~~~~ main.cpp:27:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i * 2 + 1 < H.size() ){ ~~~~~~~~~~^~~~~~~~~~ main.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( i * 2 + 2 < H.size() ){ ~~~~~~~~~~^~~~~~~~~~ main.cpp:26:13: warning: unused variable 'j' [-Wunused-variable] int j; ^