Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Super Ugly Number in C++
We have to create one function to find the nth super ugly number. The super ugly numbers are positive numbers whose all prime factors are in the given prime list primes of size k. So if the n is 12 and primes are [2, 7, 13, 19], then the output will be 32, this is because [1, 2, 4, 7, 8, 13, 14, 16, 19, 26, 28, 32] is the sequence of 12 super ugly numbers.
To solve this, we will follow these steps −
Create a data structure triplet, with num, prime and idx
if n is 1, then return 1, create an array of size n + 1, and fill this with 1
define a priority queue pq
for i in range 0 to size of primes−
create triplets t(primes[i], primes[i], 2)
for i in range 2 to n
curr := top element of pq, then delete from pq
val := num of curr
v[i] := val
num of curr := prime of curr * v[index of curr]
increase index of curr by 1
insert curr into pq
while val = num of pq top,
curr := top of pq and delete from pq
num of curr := prime of curr * v[index of curr]
increase index of curr by 1
insert curr into pq
return v[n]
Example (C++)
Let us see the following implementation to get a better understanding −
#include <bits/stdc++.h>
using namespace std;
struct Data{
int num, prime, idx;
Data(int a, int b, int c){
num = a;
prime = b;
idx = c;
}
};
struct Comparator{
bool operator()(Data a, Data b){
return !(a.num < b.num);
}
};
class Solution {
public:
int nthSuperUglyNumber(int n, vector<int>& primes) {
if(n == 1)return 1;
vector <int> v(n + 1, 1);
priority_queue < Data, vector < Data >, Comparator > pq;
for(int i = 0; i < primes.size(); i++){
pq.push(Data(primes[i], primes[i], 2));
}
int x;
for(int i = 2; i <= n; i++){
Data curr = pq.top();
pq.pop();
int val = curr.num;
v[i] = val;
curr.num = curr.prime * v[curr.idx];
curr.idx++;
pq.push(curr);
while(val == pq.top().num){
curr = pq.top();
pq.pop();
curr.num = curr.prime * v[curr.idx];
curr.idx++;
pq.push(curr);
}
}
return v[n];
}
};
main(){
Solution ob;
vector<int> v = {2,7,13,19};
cout << (ob.nthSuperUglyNumber(12, v));
}Input
12 [2,7,13,19]
Output
32
230 Views
To Continue Learning Please Login