First take a map, iterate through array once and calculate number of balls for each number i.e. m[a[i]]++;

Now iterate through map and calculate sum of number of ways of choosing 2 balls for each number for(auto i:m) total_count+=((i.second)(i.second-1))/2

Now all you need to do is to go through the array one more time and print total_count-m[a[i]]*(m[a[i]]-1)/2+(m[a[i]]-1)*(m[a[i]]-2)/2 for each element.

Idea is to first subtract number of ways of choosing two balls from m[a[i]] balls and then add number of ways of choosing two balls from m[a[i]]-1 balls.

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