Main.cc: In function 'int main()': Main.cc:7:14: error: expected primary-expression before '<=' token for(int i=1;<=a;i++){ ^ Main.cc:12:12: error: invalid types 'int[int]' for array subscript while((a[i]!=c)&&(i<=a)){ ^ Main.cc:20:12: error: invalid types 'int[int]' for array subscript while((a[i]==c)&&(i<=a)){ ^ Main.cc:5:21: warning: unused variable 'd' [-Wunused-variable] int a,b[2001],c,d=0; ^