easy.cpp: In function ‘int main()’:
easy.cpp:3:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
int main(){scanf("%d",&b);
^
easy.cpp:4:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
for(i=0;i<b;i++)scanf("%d",&a[i]);
^
/tmp/cc1PlnGh.o: In function `main':
easy.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccJf5HMW.o:grader.cpp:(.text.startup+0x0): first defined here
/tmp/ccJf5HMW.o: In function `main':
grader.cpp:(.text.startup+0x97): undefined reference to `CountPair(int, int*)'
collect2: error: ld returned 1 exit status