Compilare: main.cpp: In function 'int search1(int, int)': main.cpp:14:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ( i < l[nl].size() && l[nl][i] != x ) { ~~^~~~~~~~~~~~~~ main.cpp:17:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( i >= l[nl].size() ) { ~~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:28:26: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d", &n ); ^ main.cpp:30:35: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d%d", &op, &x ); ^