fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. vector<int>getprefixMax(vector<int>&arr){
  4. 	int n=arr.size();
  5. 	vector<int>newprefixSum(n+1,0);
  6. 	int curr=arr[1];
  7. 	newprefixSum[1]=arr[1];
  8. 	for(int i=2;i<=n;i++){
  9. 		curr=max({0,curr+arr[i],arr[i]});
  10. 		newprefixSum[i]=curr;
  11. 	}
  12. 	return newprefixSum;
  13.  
  14. }
  15. vector<int>getsuffixMax(vector<int>&arr){
  16. 	int n=arr.size();
  17. 	vector<int>newsuffixSum(n+1,0);
  18. 	int curr=arr[n];
  19. 	newsuffixSum[n]=arr[n];
  20. 	for(int i=n-1;i>0;i--){
  21. 		curr=max({0,curr+arr[i],arr[i]});
  22. 		newsuffixSum[i]=curr;
  23. 	}
  24. 	return newsuffixSum;
  25.  
  26. }
  27.  
  28. int getMaxSum(vector<int>&arr){
  29. 	int n=arr.size();
  30. 	if(n==0){
  31. 		return 0;
  32. 	}
  33. 	vector<int>prefixMax=getprefixMax(arr);
  34. 	vector<int>suffixMax=getsuffixMax(arr);
  35.  
  36. 	vector<int>finalprefixMax(n+2,0);
  37. 	vector<int>finalsuffixMax(n+2,0);
  38.  
  39. 	finalprefixMax[1]=prefixMax[1];
  40. 	for(int i=2;i<=n;i++){
  41. 		finalprefixMax[i]=max(finalprefixMax[i-1],prefixMax[i]);
  42. 	}
  43.  
  44. 	finalsuffixMax[n]=suffixMax[n];
  45. 	for(int i=n-1;i>0;i--){
  46. 		finalsuffixMax[i]=max(finalsuffixMax[i+1],suffixMax[i]);
  47. 	}
  48. 	int finalMax=0;
  49. 	for(int i=0;i<=n;i++){
  50. 		finalMax=max({finalMax,finalprefixMax[i]+finalsuffixMax[i+1]});
  51. 	}
  52. 	return finalMax;
  53.  
  54. }
  55.  
  56. int main() {
  57. 	// your code goes here
  58. 	int n;
  59. 	cin>>n;
  60. 	vector<int>arr(n+1);
  61. 	for(int i=1;i<=n;i++){
  62. 		cin>>arr[i];
  63. 	}
  64. 	cout<<"The maximum sum of non-overlapping subarrays is:"<<getMaxSum(arr);
  65.  
  66.  
  67. 	return 0;
  68. }
Success #stdin #stdout 0.01s 5276KB
comments (?)
stdin
copy 
7
1 5 -3 4 -9 9 2
stdout
copy 
The maximum sum of non-overlapping subarrays is:18
https://ideone.com/UNQLT7
language:
C++ (gcc 8.3)
created:
3 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!