1、最简单的暴力
直接遍历整个数组
public boolean Find(int target, int [][] array) {
if(array == null)
return false;
for(int i = 0; i < array.length; i++) {
for(int j = 0; j < array[i].length; j++)
if(target == array[i][j])
return true;
}
return false;
}
2、暴力上的改进
每一行都是顺序的，对每一行进行二分查找
public boolean Find(int target, int [][] array) {
if(array == null)
return false;
for(int i = 0; i < array.length; i++) {
int left = 0;
int right = array[i].length - 1;
int mid = 0;
while(left <= right){
mid = (left + right) / 2;
if(target > array[i][mid]){
left = mid + 1;
} else if (target < array[i][mid]) {
right = mid - 1;
} else if (target == array[i][mid])
return true;
}
}
return false;
}
3、运用规律
去右上角，比它大的下移，比它小的左移
public boolean Find(int target, int [][] array) {
if(array == null)
return false;
int i = array.length - 1;
int j = 0;
while(i >= 0 && j < array[0].length) {
if(target < array[i][j])
i--;
else if(target > array[i][j])
j++;
else if(target == array[i][j])
return true;
}
return false;
}
原文：https://www.cnblogs.com/wisdomzhang/p/10426132.html