i am not identifying my mistake , since giving correct output on codeblocks but not accepted

#include<bits/stdc++.h>
using namespace std;
main()
{
    long long int t,n,d,a[100],sum=0,p=0,i;
    cin>>t;
    while(t--){
        cin>>n>>d;
        for(i=0;i<n;i++)
            cin>>a[i];
            sort(a,a+n,greater<int>());
        for(i=0;i<n;i++){
            sum=sum+a[i];
            if(sum==d){
                p=1;
                break;
            }
            else if(sum>d){
                sum=sum-a[i];
            }
            else
                sum=sum;
        }
        if(p==0)
            cout<<"No"<<endl;
        else
            cout<<"Yes"<<endl;
        p=0;
        sum=0;
    }
}

codechef easy marcha1

Asked by: Deepak_kumar_Shaw on April 7, 2019, 6:34 p.m. Last updated on April 7, 2019, 6:34 p.m.

1 Answer(s)

Your code fails for the following test case:

3 7

Correct Output : Yes

You are assuming that notes of value lower than the required value will always be included. But, this may not be the case as in the above test case we can make 7 without including 1 and 3.

The idea here is to generate all the possible combinations of notes and check whether there exists any such combination in which the sum of notes is equal to the sum required. In the above test case total combinations possible will be 2^3 :

NIL

1 3

1 7

3 7

1 3 7

Out of which the correct answer is the 4th combination. So, try generating all subsets and find its sum. If any sum is equal to required sum then output will be yes else no.

Refer to this link to know more about subset generation : https://www.geeksforgeeks.org/print-sums-subsets-given-set/

Chetan_Garg last updated on April 7, 2019, 6:34 p.m. 0 Reply Upvote

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i am not identifying my mistake , since giving correct output on codeblocks but not accepted

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