2021.02.15 연습

 

  • 사용언어 : java

 

class Solution {
    public int findNumbers(int[] nums) {
        
        
        int count = 0;
        
        for (int i : nums) {
            if ( ((int)Math.log10(i)+1)%2 == 0) {
                count++;
            }
        }
        return count;
        
    }
}

Runtime: 1 ms, faster than 94.54% of Java online submissions for Find Numbers with Even Number of Digits. Memory Usage: 38.3 MB, less than 95.86% of Java online submissions for Find Numbers with Even Number of Digits.

2021.02.12 연습 (설연휴 본가서 푼것)

 

class Solution {
    public int numberOfMatches(int n) {
        
        int result = 0;
        
        
        while ( n > 1) {
            if (n%2 == 0) { //even
                n = n/2;
                result += n;
            } else { //odd
                result += (n-1)/2;
                n = (n-1)/2 + 1;
            }

        }
        
        
        return result;
    }
}

class Solution {
    public int largestAltitude(int[] gain) {
        
        int result = 0;
        int nextPoint = 0;
        
        for (int i : gain) {
            
            nextPoint = nextPoint + i;
            result = Math.max(result, nextPoint);

        }
        
        return result;
        
    }
}

2021.02.13 연습

 


class Solution {
    public int countGoodTriplets(int[] arr, int a, int b, int c) {
        
        int result = 0;
        
        for (int i =0; i < arr.length; i ++) {
            for (int j=i+1; j < arr.length; j++) {
                for (int k=j+1; k<arr.length; k++) {  

                        if ( Math.abs(arr[i]-arr[j]) <=a 
                            && Math.abs(arr[j]-arr[k]) <=b 
                            && Math.abs(arr[i]-arr[k]) <=c ) {
                            result++;
                        }
                   
                }
            }
            
        }
        
        return result;
        
    }
}

Runtime: 13 ms, faster than 69.06% of Java online submissions for Count Good Triplets. Memory Usage: 36.7 MB, less than 54.24% of Java online submissions for Count Good Triplets.

  • 다른 코드 참고
class Solution {
    public int countGoodTriplets(int[] arr, int a, int b, int c) {
        int output = 0;
        
        for(int i = 0; i < arr.length -2; i++)
            for(int j = i+1; j < arr.length -1; j++)
                if(Math.abs(arr[i] - arr[j]) <= a)
                    for(int k = j+1; k < arr.length; k++)
                        if(Math.abs(arr[j] - arr[k]) <= b)
                            if(Math.abs(arr[i] - arr[k]) <= c)
                                output++;

        return output;
    }
}