1、原题如下:
Write a program to find the nth super ugly number.
Super ugly numbers are positive numbers whose all prime factors are in the given prime list primes of size k. For example, [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.
Note:
(1) 1 is a super ugly number for any given primes.
(2) The given numbers in primes are in ascending order.
(3) 0 < k ≤ 100, 0 < n ≤ 106, 0 < primes[i] < 1000.
2、解题如下:
class Solution {
public:
int nthSuperUglyNumber(int n, vector<int>& primes) {
int size=primes.size();
vector<int> count(size, 0), ugly_num(n, INT_MAX);
ugly_num[0]=1;
for(int i=1; i<n; i++){
for(int j=0; j<primes.size(); j++){
ugly_num[i]=min(ugly_num[i],ugly_num[count[j]]*primes[j]);
}
for(int j=0; j<primes.size(); j++){
count[j]+=(ugly_num[i]==ugly_num[count[j]]*primes[j]);
}
}
return ugly_num[n-1];
}
};