bucket_sort.java

public class bucket_sort {
	 public int heightChecker(int[] heights) {
	        int[] heightToFreq = new int[101];
	        
	        for (int height : heights) {
	            heightToFreq[height]++;
	        }
	        
	        int result = 0;
	        int curHeight = 0;
	        
	        for (int i = 0; i < heights.length; i++) {
	            while (heightToFreq[curHeight] == 0) {
	                curHeight++;
	            }
	            
	            if (curHeight != heights[i]) {
	                result++;
	            }
	            heightToFreq[curHeight]--;
	        }
	        
	        return result;
	    }
}