Vpropel VIT | POD | 17/05/2020 | Triplet Sum | 38

Question(triplet_sum).txt

Triplet Sum
Given an array of numbers find unique triplets such that the sum of the triplets is zero. 
The solution set must not contain duplicate triplets.Find the number of such triplets in the array

Example:-

Given array nums = [-1, 0, 1, 2, -1, -4],

 

A solution set is:

[

  [-1, 0, 1],

  [-1, -1, 2]

]

Therefore the required output  is 2 

Input format:-

Number of elements in an array

Next  line –n elements of array separated by a comma

Output format:-

Number of triplets

triplet_sum.cpp

#include<iostream>
#include<string>
#include<vector>
#include<sstream>
#include<algorithm>
#include<iterator>
void No_triplets(std::vector<int> &v)
{
    int n=v.size();
    std::vector<std::vector<int>>result;
    for(int i=0;i<n-2;i++)
        for(int j=i+1;j<n-1;j++)
            for(int k=j+1;k<n;k++)
                if(v[i]+v[j]+v[k]==0)
                {
                    std::vector<int> temp={v[i],v[j],v[k]};
                    std::vector<int>::iterator itr=temp.begin();
                    //std::sort(itr,itr+sizeof(temp)/sizeof(temp[0]));  //##It will get wrong, because sizeof(vector) creates problem -:( remember:)
                    std::sort(itr,itr+temp.size());
                    //std::sort(temp.begin(),temp.end());
                    bool chk=false;
                    for(std::vector<int> t:result)
                        if(t==temp)
                            chk=true;
                    if(chk==false)
                        result.push_back(temp);
                }
    /*  # To see our triplets :)
    for(auto i:result)
        {
        for(auto j:i)
            cout<<j<<'\t';
        cout<<endl;
        }
    */
    std::cout<<result.size();
}
int main()
{
    int n;
    std::cin>>n;
    std::string st;
    std::cin>>st;
    std::vector<int> v;
    std::stringstream ss(st);
    std::cin.ignore();
    while(ss.good())
    {
        std::string substr; 
        std::getline(ss, substr, ','); 
        int temp;
        std::stringstream ss_temp(substr);
        ss_temp>>temp;
        v.push_back(temp);
    }
    /*
    for(int  &i:v)
        cout<<i<<'\t';
    */
    No_triplets(v);
    return 0;
}
//                                              ### Thank YOu :) 
//                                                @cs_jawanda
//                                         .Chiranjeet Singh Jawanda.
//                                                VIT VELLORE

triplet_sum.java

import java.util.Scanner;
import java.util.Arrays;
public class Main
{
    public static void NumTriplets(int arr[],int n)
    {
        int container[][]=new int[30][3]; // assume big size initially
        int count=0;
        for(int i=0;i<n-2;i++)
            for(int j=i+1;j<n-1;j++)
                for(int k=j+1;k<n;k++)
                {
                    if(arr[i]+arr[j]+arr[k]==0)
                    {
                        int temp[]={arr[i],arr[j],arr[k]};
                        Arrays.sort(temp);
                        boolean chk=false;
                        for(int []t:container)
                        {
                            if(Arrays.equals(temp,t))
                                chk=true;
                        }
                        if(chk==false)
                        {
                            for(int t=0;t<3;t++)
                                {
                                    container[count][t]=temp[t];
                                }
                            count++;
                        }
                        
                    }
                }
        System.out.print(count);
    }
    public static void main(String[] args)
    {
        Scanner s=new Scanner(System.in);
        int n=s.nextInt();
        String str=s.next();
        String []nums=str.split(",");
        int number[]=new int[n];
        for(int i=0;i<n;i++)
            number[i]=Integer.parseInt(nums[i]);
        NumTriplets(number,n);
            
    }
} 
//                                              ### Thank YOu :) 
//                                                @cs_jawanda
//                                         .Chiranjeet Singh Jawanda.
//                                                VIT VELLORE

triplet_sum.py

n=int(input())
l=[]
m=list()
l=input().split(",")
l=[int(x) for x in l]
for i in range(n-2):
    for j in range(i+1,n-1):
        for k in range(j+1,n):
            if l[i]+l[j]+l[k]==0:
                temp=[l[i],l[j],l[k]]
                temp.sort()
                if temp not in m:
                    m.append(temp)
print(len(m))
'''
//                                              ### Thank YOu :) 
//                                                @cs_jawanda
//                                         .Chiranjeet Singh Jawanda.
//                                                VIT VELLORE
'''

https://www.geeksforgeeks.org/find-triplets-array-whose-sum-equal-zero/