41 lines
1.3 KiB
C++
41 lines
1.3 KiB
C++
#include <vector>
|
|
#include <cstdio>
|
|
|
|
/**
|
|
* 39. Combination Sum
|
|
* Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.
|
|
* The same number may be chosen from candidates an unlimited number of times. Two combinations are unique if the frequency of at least one of the chosen numbers is different.
|
|
* It is guaranteed that the number of unique combinations that sum up to target is less than 150 combinations for the given input.
|
|
*/
|
|
|
|
class Solution {
|
|
public:
|
|
static std::vector<std::vector<int>> combinationSum(const std::vector<int>& candidates, int target, int prev = 0) {
|
|
std::vector<std::vector<int>> ret;
|
|
for (int v : candidates) {
|
|
if (v >= prev && target - v >= v) {
|
|
std::vector<std::vector<int>> t = combinationSum(candidates, target - v, v);
|
|
for (std::vector<int>& i : t) {
|
|
i.push_back(v);
|
|
}
|
|
ret.reserve(ret.size() + t.size());
|
|
ret.insert(ret.end(), t.begin(), t.end());
|
|
} else if (v == target) {
|
|
ret.emplace_back(1, v);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
};
|
|
|
|
int main() {
|
|
auto ret = Solution::combinationSum({2, 3, 5}, 8);
|
|
for (const auto& i : ret) {
|
|
for (auto j : i) {
|
|
std::printf("%d ", j);
|
|
}
|
|
std::printf("\n");
|
|
}
|
|
return 0;
|
|
}
|