minimum length of sub-array which sum equal to a given value(Sliding Window Technique).cpp

 /// Its Work For Positive Value

/*

if array size n = 10

array is :: 4 2 2 0 0 5 3 8 7 1

and value is :: 8

Then minimum length sub-array is : [8]

so minimum length : 1

*/

#include<bits/stdc++.h>

using namespace std;

int minimum_length(int a[], int n, int value)

{

int currentsum = 0, minlength = n+1;

int start = 0, finish = 0;

while(finish < n)

{

while(currentsum < value && finish < n)

currentsum += a[finish++];

while(currentsum > value && start < finish)

currentsum -= a[start++];

while(currentsum == value && start < n)

{

if(finish-start < minlength)

minlength = finish - start;

currentsum -= a[start++];

}

}

return minlength;

}

int main()

{

int n, value;

cout << "Enter Array Size :: ";

cin >> n;

int a[n];

cout << "\nEnter Array Element :: ";

for(int i=0;i<n;i++)

cin >> a[i];

cout << "\nEnter a value :: ";

cin >> value;

int mn = minimum_length(a, n, value);

cout << "\nMinimum Length :: " << mn << "\n";

return 0;

}