Main.cc: In function ‘bool cmp(s, s)’: Main.cc:10:11: error: ‘struct s’ has no member named ‘score’ return a.score>b.score; ^~~~~ Main.cc:10:19: error: ‘struct s’ has no member named ‘score’ return a.score>b.score; ^~~~~ Main.cc: In function ‘int main()’: Main.cc:21:2: error: ‘sort’ was not declared in this scope sort(a+1,a+1+x,cmp); ^~~~ Main.cc:21:2: note: suggested alternative: ‘qsort’ sort(a+1,a+1+x,cmp); ^~~~ qsort