To prove safety offer face questions 4 (java version): two-dimensional array lookup

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Interview questions 4: a two-dimensional array to find

Thinking

• Compare the top right corner to find the numbers and size of digital relationship
• If the number is greater than the upper-right corner of the digital're looking for, where the top-right corner of the digital ignored
• If the number is less than the number you want to find the top right corner of the row numbers where the upper right corner are ignored

the complexity

• time complexity:
• Space complexity:

public class Solution {
    public boolean Find(int target, int [][] array) {
        // 健壮性判断
        if(array.length <=0 ){
            return false;
        }
        // 正式判断; 判断右上角的元素和要查找的元素的大小关系, 结果有三种可能: 1,忽略列, 2,忽略行, 3,返回true   把这三种情况想清楚了, 这题就简单了
        int row = 0;
        int col = array[0].length - 1;
        while(row <= array.length - 1 && col >= 0){
            if(array[row][col] == target)
                return true;
            else if(array[row][col] > target)
                col--;
            else 
                row++;
        }
        return false;
    }
}