Create: 0377-combination-sum-iv.cpp

cpp/0377-combination-sum-iv.cpp

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+/*
+ Given an array of distinct integers nums and a target integer 'target', 
+ return the number of possible combinations that add up to target.
+ 
+ Ex. nums = [1,2,3] target = 4
+ Possible Combinations: (1,1,1,1) (1,1,2) (1,2,1) (1,3) (2,1,1,)
+ (2,2) (3,1). 
+ So, total number of combinations possible is 7.
+
+ Time: O(n * m)
+ Space: O(m)
+*/
+
+class Solution {
+public:
+ int combinationSum4(vector<int>& nums, int target) {
+ sort(nums.begin(), nums.end());
+ vector<unsigned int> dp(target+1, 0);
+ dp[0] = 1;
+ for(int total=1; total<=target; total++) {
+ for(int i=0; i<nums.size(); i++) {
+ if(nums[i] <= total) dp[total] += dp[total - nums[i]];
+ else break;
+ }
+ }
+ return dp[target];
+ }
+};