Pair With Given Difference

Pair With Given Difference - InterviewBitInterviewBit

Using set/map

Same as two sum.

x - y = 7 => y = x - 7
y - x = 7 => y = x + 7

For each x in A 
    see if we have y using both the equations.

int Solution::solve(vector<int> &A, int B) {
    unordered_set<int> s;
    for(int x: A) 
        if(s.count(B + x) || s.count(x - B))
            return true;
        else 
            s.insert(x);
    
    return false;
}