From 403e3645050abbd4f359410369bbd10d209a2bd8 Mon Sep 17 00:00:00 2001
From: Aakarsh Verma <aakarsh2126@yahoo.com>
Date: Thu, 17 Oct 2019 22:29:05 +0530
Subject: [PATCH] kthpermutationsequence.cpp

---
 Backtracking/kthpermutationsequence.cpp | 79 +++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 Backtracking/kthpermutationsequence.cpp

diff --git a/Backtracking/kthpermutationsequence.cpp b/Backtracking/kthpermutationsequence.cpp
new file mode 100644
index 0000000..696605f
--- /dev/null
+++ b/Backtracking/kthpermutationsequence.cpp
@@ -0,0 +1,79 @@
+#include <bits/stdc++.h>
+using namespace std;
+bool flag=false;
+int factorial(int n){
+    /*if(n>12){
+        return INT_MAX;
+        return 0;
+    }*/
+    int p=1;
+    int i;
+    for(i=1;i<=n;i++){
+        p*=i;
+    }
+    return p;
+}
+void permute(int index,int n,int k,int *c,string *st,vector<int>&v){
+    if(index>=n){
+        (*c)++;
+//        cout<<(*c)<<endl;
+        if((*c)==k){
+            int i;
+            for(i=0;i<n;i++){
+                ostringstream str1; 
+                str1<<v[i];  
+                (*st)+=str1.str();
+            }
+            flag=true;
+//            cout<<s<<endl;
+            return;        
+        }
+        return;
+    } 
+    int i,temp;
+    for(i=index;i<n;i++){
+        if((*c)==k){
+            return;
+        }
+        temp=v[index];
+        v[index]=v[i];
+        v[i]=temp;
+        permute(index+1,n,k,c,st,v);
+        temp=v[index];
+        v[index]=v[i];
+        v[i]=temp;
+    }
+}
+string Solution::getPermutation(int A, int B) {
+    int i,n,k,x;
+    n=A;
+    k=B;
+    int f=factorial(n);
+    vector<int>v;
+    for(i=1;i<=n;i++){
+        v.push_back(i);
+    }
+    string s;
+    // if(k>f){
+    //     k=k%f;
+    // }
+   
+    // for(i=0;i<n;i++){
+    //     ostringstream str1; 
+    //     str1<<v[i];  
+    //     s+=str1.str();    
+    // }
+    int cnt=1;
+    while(cnt<k){
+        next_permutation(v.begin(),v.end());
+        cnt++;
+    }
+    for(i=0;i<n;i++){
+        ostringstream str1; 
+        str1<<v[i];  
+        s+=str1.str();    
+    }
+//    permute(0,n,k,&cnt,&s,v);
+//    cout<<s<<endl;
+    return s;
+}