240. 搜索二维矩阵 II
TAG：二分
链接： https://leetcode.cn/problems/search-a-2d-matrix-ii/
class Solution {
public:
bool searchMatrix(vector<vector<int>>& matrix, int target) {
int m = matrix.size();
int n = matrix[0].size();
int i = m - 1, j = 0;
while (i >= 0 && j < n) {
if (target > matrix[i][j])
j++;
else if (target < matrix[i][j])
i--;
else
return true;
}
return false;
}
};
378. 有序矩阵中第 K 小的元素
链接：https://leetcode.cn/problems/kth-smallest-element-in-a-sorted-matrix/
TAG：优先队列
class Solution {
public:
int kthSmallest(vector<vector<int>>& matrix, int k) {
priority_queue<int, vector<int>, less<int>> pq;
for (int i = 0; i < matrix.size(); i++) {
for (int j = 0; j < matrix[0].size(); j++) {
pq.push(matrix[i][j]);
if (pq.size() > k)
pq.pop();
}
}
return pq.top();
}
};