Minimize the absolute difference

• Time : $O(|A| + |B| + |C|)$
• Space : $O(1)$

int Solution::solve(vector<int> &A, vector<int> &B, vector<int> &C) {
    int i = 0, j = 0, k = 0, res = INT_MAX;
    int sa = A.size(), sb = B.size(), sc = C.size();
    while(i < A.size() or j < B.size() or k < C.size()) {
        int a = A[min(i,sa-1)], b = B[min(j,sb-1)], c = C[min(k,sc-1)];
        int ma = max({a,b,c}), mi = min({a,b,c});
        res = min(res, abs(ma - mi));
        if(i < sa and a == mi) i += 1;
        else if(j < sb and b == mi) j += 1;
        else if(k < sc and c == mi) k += 1;
        else break;
    }
    return res;
}