ugly numbers code example

Example: ugly number code in c++

# include<iostream>
using namespace std;
int min(int x, int y, int z){ //find smallest among three numbers
   if(x < y){
      if(x < z)
         return x;
      else
         return z;
   }
   else{
      if(y < z)
         return y;
      else
         return z;
   }
}
int getUglyNum(int n){
   int uglyNum[n]; // To store ugly numbers
   int i2 = 0, i3 = 0, i5 = 0;
   //find next multiple as 1*2, 1*3, 1*5
   int next2mul = 2;
   int next3mul = 3;
   int next5mul = 5;
   int next = 1; //initially the ugly number is 1
   uglyNum[0] = 1;
   for (int i=1; i<n; i++){
      next = min(next2mul, next3mul, next5mul); //find next ugly number
      uglyNum[i] = next;
      if (next == next2mul){
         i2++; //increase iterator of ugly numbers whose factor is 2
         next2mul = uglyNum[i2]*2;
      }
      if (next == next3mul){
         i3++; //increase iterator of ugly numbers whose factor is 3
         next3mul = uglyNum[i3]*3;
      }
      if (next == next5mul){
         i5++; //increase iterator of ugly numbers whose factor is 5
         next5mul = uglyNum[i5]*5;
      }
   }
   return next; //the nth ugly number
}
int main(){
   int n;
   cout << "Enter term: "; cin >> n;
   cout << n << "th Ugly number is: " << getUglyNum(n)<< endl;
}

Tags:

Cpp Example