LeetCode 313. Super Ugly Number

思路

利用ugly,pointer,prime三个数组存储当前找到的所有ugly，同时存储下次可能是最小的数：

算法实现

public int nthSuperUglyNumber(int n, int[] primes) {
      int[] pointer = new int[primes.length];
      Arrays.fill(pointer, 0);
      int ugly[] = new int[n];
      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[pointer[j]] * primes[j] < min){
                  min = ugly[pointer[j]] * primes[j];
                  minIndex = j;
              }else if(ugly[pointer[j]] * primes[j] == min){
                  pointer[j]++;
              }
          }
          ugly[i] = min;
          pointer[minIndex]++;
      }
      return ugly[n - 1];
}