Function mergesort

CPP/sorting/merge_sort.cpp:51–57

	 }
	}
	void mergesort(std::vector<int> &v,int s,int e){
		if(s>=e) return;
		int mid=(s+e)/2;
		mergesort(v,s,mid);
		mergesort(v,mid+1,e);
		return merge(v,s,e);
	}
	int main(){
	//cin.tie(0)->sync_with_stdio(0);
		int n;