leetcode/src/s0047_permutations_ii.cpp
2023-02-03 17:01:25 +08:00

34 lines
948 B
C++

#include "s0047_permutations_ii.hpp"
void permuteUniqueDFS(vector<int> &path, vector<vector<int>> &result,
vector<bool> &used, vector<int> &nums, int startIndex) {
int len = nums.size();
// 终止条件
if (path.size() == len) {
result.push_back(path);
return;
}
// 开始迭代
for (int i{0}; i < len; ++i) {
// 如果当前元素在树层使用过,则跳过
if (used[i] || (i > 0 && nums[i] == nums[i - 1] && used[i - 1] == false))
continue;
// 否则处理当前节点
path.push_back(nums[i]);
used[i] = true;
permuteUniqueDFS(path, result, used, nums, i + 1);
used[i] = false;
path.pop_back();
}
}
vector<vector<int>> S0047::permuteUnique(vector<int> &nums) {
vector<int> path{};
vector<vector<int>> result{};
vector<bool> used(nums.size(), false);
sort(nums.begin(), nums.end());
permuteUniqueDFS(path, result, used, nums, 0);
return result;
}