Find Minimum difference pair [ Amazon Interview Question]

Problem: Find the minimum difference between any pair in an unsorted  array. #include <stdio.h> #include <algorithm> #include <iostream> using namespace std; int arr[105]; int res[100005]; int main() { int t,n,k,a; scanf("%d",&t); while(t–) { scanf("%d",&n); for(int i=0;i<105;i++) arr[i]=0; for(int i=0;i<n;i++) { scanf("%d",&a); arr[a]++; } //sort(arr,arr+n); k=0; for(int i=0;i<105;i++) { if(arr[i]==0) continue; for(int j=1;j<=arr[i];j++) res[k++]=i; } int

Tree construction a Binary Tree from Postorder and Inorder traversal [Amazon, Adobe]

Problem: Provided Inorder and PostOrder of a tree. Construct the tree and print it in PreOrder traversal. #include <stdio.h> #include <iostream> #include <string.h> #include<stdlib.h> #include <string> using namespace std; struct Node{ int data; Node *left; Node *right; }; int search(int in[],int in_stIndex,int in_endIndex,int data) { for(int i=in_stIndex;i<=in_endIndex;i++) { if(in[i]==data) return i; } } void pintPreOrder(Node*

Tree construction from Inorder & Preorder [ Microsoft ]

Problem: Provided Inorder and PreOrder of a tree. Construct the tree and print it in PostOrder traversal. #include <stdio.h> #include <iostream> #include <string.h> #include<stdlib.h> #include <string> using namespace std; int preOrderIdx=0; struct Node{ int data; Node *left; Node *rit; }; int search(int in[],int in_stIndex,int in_endIndex,int data) { for(int i=in_stIndex;i<=in_endIndex;i++) { if(in[i]==data) return i; } }

Count total set bits in all numbers from 1 to n [Amazon ]

Problem: Find the sum of all bits from numbers 1 to N. #include <stdio.h> int main() { //code int t,n,i,ans; int powerOfTwo,dividend,m; int arr[30]; arr[0]=1; arr[1]=2; arr[2]=5; arr[3]=13; int gapOfNumber=8; for(i=4;i<30;i++) { arr[i]=(arr[i-1])*2+(gapOfNumber-1); gapOfNumber=gapOfNumber*2; } scanf("%d",&t); while(t–) { scanf("%d",&n); ans=0; while(n) { m=n; dividend=1; powerOfTwo=0; while(m) { if(m/2) { powerOfTwo+=1; dividend*=2; m=m/2; } else break;

Count Number of subsequences of the form a^i b^j c^k [Amazon]

Problem: Find the number  of subsequences of the form aibjck, i.e., it consists of i number of  ’a’ characters, followed by j  i number of  ’b’ characters, followed by k  i number of  ’c’ characters where i >= 1, j >=1 and k >= 1 from a given string S. #include <stdio.h> #include <string.h> int

Matrix Exponentiation algorithm

Related studies: Here Problem Link Problem description: The laboratory of Microbiology department has been attacked by several robbers recently. They robbed and stole many valuable samples of viruses, bacteria, microorganisms. While being in hurry, they broke a tube. The tube contained sample of one of the most dangerous germs called Dangerm. The tube contained exactly

Count of n digit numbers whose sum of digits equals to given sum [ Amazon ]

Problem: Given two integers ‘n’ and ‘sum’, find count of all n digit numbers with sum of digits as ‘sum’. Leading 0’s are not counted as digits. Print your output % 10^9+7. #include <stdio.h> #define MOD 1000000007 unsigned long long dp[101][1001]; unsigned long long Count(int n,int sum) { int i; if(n==0) { if(sum==0) return 1; return