Find four elements a b c and d in an array such that a b c d using hashmap
Answers
Answer:
If you know programming in java
then this solution might help you.
Step-by-step explanation:
public static ArrayList<Integer> find(int[] num,int n){
ArrayList<Integer> ans = new ArrayList<>();
HashMap<Integer,Pair> hm = new HashMap<>();
for (int i = 0; i < n; i++) {
for (int j = i+1; j < n; j++) {
if (i == j) {
} else {
int x = num[i] + num[j];
if (!hm.containsKey(x)) {
hm.put(x, new Pair(i, j));
} else {
Pair p = hm.get(x);
ans.add(p.n1);
ans.add(p.n2);
ans.add(i);
ans.add(j);
// ans.add(e)
return ans;
}
}
}
}
return new ArrayList<>();
}
public static class Pair{
int n1;
int n2;
public Pair(int n1,int n2) {
this.n1 = n1;
this.n2 = n2;
}
}
}