1051. Height Checker

class Solution {
    public int heightChecker(int[] heights) {
        int n=heights.length;
        int i,c=0;
        int a[] = new int[n];
        for(i=0;i<n;i++)
            a[i]=heights[i];
        Arrays.sort(a);
        for(i=0;i<n;i++)
            if(a[i]!=heights[i])
                c++;
        return c;
        
    }
}