Compilare: user.cpp: In function ‘void insert_hash(int, int)’: user.cpp:21:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<H[nr1].size()&&H[nr1][i].val!=nr2) ^ user.cpp:23:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==H[nr1].size()) ^ user.cpp: In function ‘int find_hash(int, int)’: user.cpp:31:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<H[nr1].size()&&H[nr1][i].val!=nr2) ^ user.cpp:33:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(H[nr1].size()==i) ^ user.cpp: In function ‘int main()’: user.cpp:43:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&n); ^ user.cpp:57:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&m); ^