Walmart Labs Interview Question for SDE1s

Country: United States
Interview Type: Written Test

Comment hidden because of low score. Click to expand.
0
of 2 vote

O(n^2). pseudo code:

``````for (a in A) {
for (b in B) {
insert(a+b, hashtable);
}
}

for (b in B) {
for (c in C) {
if (b+c in hashtable) {
// blah
}
}
}``````

Comment hidden because of low score. Click to expand.
0
of 0 vote

SPACE: N^2
COMPLEXITY: N^2

``````package com.test.src;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.stream.Collectors;

/**
* Given 3 unsorted arrays A, B and C you need to find all possible combinations
* such that A[i] + B[j] = B[k] + C[l].
*
* - venkataratnamkumar7777 11 months ago in United States | Report Duplicate |
* Flag |
*
*
* @author agupta13
*
*/
public class FourArraySumEqualityFinder {

public static void main(String... args) {
List<Integer> A = Arrays.asList(args[0].split("")).stream().map(s -> Integer.parseInt(s))
.collect(Collectors.toList());
List<Integer> B = Arrays.asList(args[1].split("")).stream().map(s -> Integer.parseInt(s))
.collect(Collectors.toList());
List<Integer> C = Arrays.asList(args[2].split("")).stream().map(s -> Integer.parseInt(s))
.collect(Collectors.toList());

System.out.println(combinationFinder(A, B, C));
}

// A[i] + B[j] = B[k] + C[l]
private static Integer combinationFinder(List<Integer> A, List<Integer> B, List<Integer> C) {
Integer combinations = 0;
Map<Integer, Integer> sumOfABMap = new HashMap<>();
Map<Integer, Integer> sumOfBCMap = new HashMap<>();
for (Integer a : A) {
for (Integer b : B) {
Integer sum = a + b;
Integer counter = 0;
if (sumOfABMap.containsKey(sum)) {
counter = sumOfABMap.get(sum) + 1;
}
sumOfABMap.put(sum, counter);
}
}

for (Integer b : B) {
for (Integer c : C) {
Integer sum = b + c;
Integer counter = 0;
if (sumOfBCMap.containsKey(sum)) {
counter = sumOfBCMap.get(sum) + 1;
}
sumOfBCMap.put(sum, counter);
}
}

for(Entry<Integer, Integer> eSetAb : sumOfABMap.entrySet()) {
if(sumOfBCMap.containsKey(eSetAb.getKey())) {
System.out.println("eSetAb.getKey()="+ eSetAb.getKey());
combinations += eSetAb.getValue() * sumOfBCMap.get(eSetAb.getKey());
}
}

return combinations;
}
}``````

Comment hidden because of low score. Click to expand.
0
of 0 vote

vector<int>vec;
unordered_set<int>s;
for(int i=0;i<A.length();i++)
for(int j=0;j<B.length();j++)
if(s.find(A[ i ]+B[ j ])==s.end( ) )
s.insert(A[ i ]+B[ j ]);

for(int i=0;i<C.length();i++)
for(int j=0;j<B.length();j++)
if(s.find(C[ i ]+B[ j ]) !=s.end( ) )
vec.push_back(C[i]+B[ j ]);

return vec;
//conplexity:O(N^2)

Comment hidden because of low score. Click to expand.
-1
of 1 vote

Something like this should work

``````for (int i=0; i < a.length; i++)
for (int j=0; j < b.length; j++)
for (int k=0; k < b.length; k++)
for (int l=0; l < b.length; l++)
if (a[i] + b[j] == b[k] + c[l])
System.out.println(String.format("a[%d] : %d +b[%d] : %d == b[%d] : %d +c[%d] : %d",
i, a[i], j, b[j], k, b[k], l, c[l]));``````

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