 # Not so easy if you haven't done the previous questions. Solution is intuitive if you have

#1
```````void combosum(vector<vector<int>>&C, vector<int>&A, vector<int> X, int B, int sum, int index){
int i;
//First element is pushed here
X.push_back(A[index]);
sum=sum+A[index];
//If sum exceeds the desired value, return void
if(sum>B)
return;
//If sum equals the desired value, push_back the vector into the 2-D vector
if(sum==B){
C.push_back(X);
}
//The next element after the previous element is controlled by this loop
for(i=index;i<A.size();++i){
combosum(C,A,X,B,sum,i);
}
}

vector<vector<int> > Solution::combinationSum(vector<int> &A, int B) {
vector<vector<int>> C;
vector<int> X, vec;

//Sorting so that answer comes as expected output. Could also sort later.
sort(A.begin(),A.end());
int i;
//This is to remove any duplicate entries in the vector
for(i=0;i<A.size()-1;++i){
if(A[i]==A[i+1])
continue;
else
vec.push_back(A[i]);
}
vec.push_back(A[i]);
//For the first element of each vector to be pushed into the 2-D vector
for(i=0;i<A.size();++i){
combosum(C,vec,X,B,0,i);
}
return C;
}
```````