/
_313.java
executable file
·48 lines (45 loc) · 1.42 KB
/
_313.java
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package com.hit.basmath.learn.others;
/**
* 313. Super Ugly Number
* <p>
* Write a program to find the nth super ugly number.
* <p>
* Super ugly numbers are positive numbers whose all prime factors are in the given prime list primes of size k.
* <p>
* Example:
* <p>
* Input: n = 12, primes = [2,7,13,19]
* Output: 32
* <p>
* Explanation: [1,2,4,7,8,13,14,16,19,26,28,32] is the sequence of the first 12
* super ugly numbers given primes = [2,7,13,19] of size 4.
* <p>
* Note:
* <p>
* 1 is a super ugly number for any given primes.
* The given numbers in primes are in ascending order.
* 0 < k ≤ 100, 0 < n ≤ 106, 0 < primes[i] < 1000.
* The nth super ugly number is guaranteed to fit in a 32-bit signed integer.
*/
public class _313 {
public int nthSuperUglyNumber(int n, int[] primes) {
int[] ptr = new int[primes.length];
int[] ugly = new int[n + 1];
ugly[0] = 1;
for (int i = 1; i < n; i++) {
int min = Integer.MAX_VALUE;
int minIndex = 0;
for (int j = 0; j < primes.length; j++) {
if (ugly[ptr[j]] * primes[j] < min) {
min = ugly[ptr[j]] * primes[j];
minIndex = j;
} else if (ugly[ptr[j]] * primes[j] == min) {
ptr[j]++;
}
}
ugly[i] = min;
ptr[minIndex]++;
}
return ugly[n - 1];
}
}