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  1. #include<bits/stdc++.h>
  2. #define ll long long int
  3. #define vec vector<ll>
  4. #define f(var,a,b) for(ll var = a ; var < b ; var++ )
  5. #define fasthoja ios_base::sync_with_stdio(false); cin.tie(NULL);
  6. using namespace std;
  7.  
  8. //This funtion will find the maximum sum of ‘k’ 
  9. //consecutive elements in the array.
  10. ll slidingWindow( vec &v , ll k ) {
  11. // Note : here we maintain, sliding window of size k
  12.  
  13. /*	Algo : 1. Calculate sum from 0 to kth element
  14. 		   2. Now at each step take add the next (k+1)th value, and subtract the k-1th value
  15. 		   3. at each step store maximum sum, and finally return it
  16. */
  17. 	if( k > v.size() ) {
  18. //		Here window size is greater than array size hence invalid
  19. //		cout << "Invalid\n";
  20. 		return -1;
  21. 	}
  22.  
  23. 	ll sum = 0;
  24. 	f(i,0,k) sum += v[i];
  25.  
  26. 	ll maxSum = sum;
  27. 	ll index = 1;
  28.  
  29. 	f(i,k,v.size()) {
  30. 		sum += ( v[i] - v[i-k] );
  31. 		maxSum = max( maxSum , sum );
  32. 	}
  33.  
  34. 	return maxSum;
  35. }
  36.  
  37. int main(void){
  38.  
  39.     fasthoja;
  40.     ll t; cin>>t;
  41.  
  42.     while(t--){
  43.     	ll n,k; cin >> n >> k;
  44.     	vec v(n); f(i,0,n) cin >> v[i];
  45.     	cout << slidingWindow( v , k ) << "\n";
  46.     }//end of test case loop
  47.  
  48.  return 0;
  49. }
  50.  
Success #stdin #stdout 0s 4324KB
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https://ideone.com/u1NTNn
language:
C++14 (gcc 8.3)
created:
3 years ago
visibility:
secret

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