@@ -0,0 +1,60 @@
+#include<vector>
+#include<algorithm>
+#include<iostream>
+#include<unordered_map>
+using namespace std;
+
+class Solution {
+int r, c, k; // r: 矩阵的行数, c: 列数, k: 矩阵中元素的个数
+unordered_map<int, int> dict; // 大脑中构建一个映射: x -> x, 默认用这个映射, 将不满足这个映射的特殊键值对存入哈希表
+public:
+Solution(int m, int n) {
+r = m;
+c = n;
+k = r*c;
+}
+
+vector<int> flip() { /* 先把矩阵(二维数组)拉平成1维数组, 再进行随机处理 */
+int key = rand() % k;
+int val = key; // 默认的映射规则: x -> x (x的范围是: 0 -> k-1)
+if (dict.count(key))
+val = dict[key];
+
+if (!dict.count(k - 1))
+dict[k-1] = k - 1;
+// 当key处的kvp用过后, 用最后一个kvp(key = k-1)覆盖之, 然后删掉最后一个kvp, 就可以在剩下的数中实现随机化选择
+dict[key] = dict[k-1];
+dict.erase(k - 1);
+k--; // 表示删掉了末尾的一个数
+
+int newRow = val / c;
+int newCol = val % c;
+return {newRow, newCol};
+}
+
+void reset() {
+k = r*c;
+dict.clear();
+}
+};
+
+// Test
+int main()
+{
+int m = 3;
+int n = 1;
+Solution* sol = new Solution(m, n);
+vector<int> res = sol->flip();
+cout << "{" << res[0] << ", " << res[1] << "}" << endl;
+res = sol->flip();
+cout << "{" << res[0] << ", " << res[1] << "}" << endl;
+res = sol->flip();
+cout << "{" << res[0] << ", " << res[1] << "}" << endl;
+sol->reset();
+res = sol->flip();
+cout << "{" << res[0] << ", " << res[1] << "}" << endl;
+
+cout << "OK~" << endl;
+
+return 0;
+}