public class Solution { public int missingNumber(int[] nums) { int size=nums.length; int res[]=new int[size+1]; for(int i=0;i<=size;i++) { res[i]=0; } for(int i=0;i<size;i++) { res[nums[i]]=1; } int answer=0; for(int i=0;i<=size;i++) { if(res[i]==0) { answer=i; break; } } return answer; } }