C++ | Leetcode C++题解之第519题随机翻转矩阵
题目：
题解：
class Solution {
public:
Solution(int m, int n) {
this->m = m;
this->n = n;
this->total = m * n;
srand(time(nullptr));
}
vector<int> flip() {
int x = rand() % total;
vector<int> ans;
total--;
// 查找位置 x 对应的映射
if (map.count(x)) {
ans = {map[x] / n, map[x] % n};
} else {
ans = {x / n, x % n};
}
// 将位置 x 对应的映射设置为位置 total 对应的映射
if (map.count(total)) {
map[x] = map[total];
} else {
map[x] = total;
}
return ans;
}
void reset() {
total = m * n;
map.clear();
}
private:
int m;
int n;
int total;
unordered_map<int, int> map;
};