Title description
Choose n numbers from the n+1 numbers of 0,1,2,...,n to form an ordered array, find the missing number among these n numbers, and require O(n) to be as small as possible.
Example 1
enter
[0,1,2,3,4,5,7]
return value
6
import java.util.*;
public class Solution {
/**
* 找缺失数字
* @param a int整型一维数组 给定的数字串
* @return int整型
*/
public int solve (int[] a) {
if(a == null || a.length == 0){
return 0;
}
int start = a[0];
int target = 0;
for(int i=1;i<a.length;i++){
if(a[i] - a[i-1] == 1){
start = a[i];
}else{
target = start + 1;
}
}
return target;
}
}