Merge pull request #3555 from RoyCoding8/master

Added files for CPP and py for kth largest element

search/kth_largest_in_array/C++/Solution_O(n).cpp

@@ -0,0 +1,37 @@
+#include<bits/stdc++.h>
+#define ll long long
+using namespace std;
+
+ll partition(ll a[],int l,int r){
+    int k=l+rand()%(r-l+1),i=l;
+    swap(a[l],a[k]);
+    ll key=a[l];
+    for(int j=l+1;j<=r;j++){
+        if(a[j]<=key){
+            i++;
+            swap(a[i],a[j]);
+        }
+    }
+    swap(a[l],a[i]);
+    return i;
+}
+
+ll kth_largest(ll a[],ll l,ll r,ll k){
+    if(k>r-l+1||k<=0) return LLONG_MAX;
+    int p=partition(a,l,r);
+    if(p==r-k+1) return a[p];
+    if(p>r-k+1) return kth_largest(a,l,p-1,k-r+p-1);
+    return kth_largest(a,p+1,r,k);
+}
+
+int main(){
+    int n,k;
+    cin>>n>>k;
+    srand(time_t(NULL));
+    ll a[n];
+    for(int i=0;i<n;i++) cin>>a[i];
+    ll ans=kth_largest(a,0,n-1,k);
+    if(ans==LLONG_MAX) cout<<"No Kth largest element\n";
+    else cout<<ans<<'\n';
+    return 0;
+}

search/kth_largest_in_array/Python/Solution.py

@@ -0,0 +1,32 @@
+import random as rd
+
+INF =float('inf')
+
+def partition(a, l, r):
+    k = l+rd.randint(0,r-l+1)
+    a[l],a[k] = a[k],a[l]
+    key,i = a[l],l
+    for j in range(l+1,r+1):
+        if a[j]<=key:
+            i+=1
+            a[i],a[j] = a[j],a[i]
+    a[l],a[i] = a[i],a[l]
+    return i
+
+def kth_largest(a,l,r,k):
+    if k>r-l+1 or k<=0:
+        return INF
+    p = partition(a,l,r)
+    if p==r-k+1:
+        return a[p]
+    if p>r-k+1:
+        return kth_largest(a,l,p-1,k-r+p-1)
+    return kth_largest(a,p+1,r,k)
+
+n,k = map(int,input().split())
+a = list(map(int,input().split()))
+ans = kth_largest(a,0,n-1,k)
+if ans == INF:
+    print('No Kth largest element')
+else:
+    print(ans)