HIIT Generation

input/code.cpp: In function 'void update_list(std::vector<node*>&)':
input/code.cpp:38:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < cp.size(); i++) {
                  ~~^~~~~~~~~~~

#include <iostream>
#include <cmath>
#include <string>
#include <vector>
 
using namespace std;
 
typedef long long LL;
 
 
struct node {
	vector<node*> kids;
	char c;
};
 
 
vector<node*> hs;
vector<node*> is;
vector<node*> ts;
 
void expand(node * root) {
	node * h = new node(); h->c = 'H';
	node * i1 = new node(); i1->c = 'I';
	node * i2 = new node(); i2->c = 'I';
	node * t = new node(); t->c = 'T';
	root->kids.emplace_back(h);
	root->kids.emplace_back(i1);
	root->kids.emplace_back(i2);
	root->kids.emplace_back(t);
	hs.emplace_back(h);	
	is.emplace_back(i1);	
	is.emplace_back(i2);	
	ts.emplace_back(t);
}
 
 
void update_list(vector<node*> & cp) {
	for (int i = 0; i < cp.size(); i++) {
		node * n = cp[i];
		expand(n);
	}
}
 
 
void expand_char(char c) {
	if (c == 'H') {
		vector<node*> hcp = hs;
		hs.clear();
		update_list(hcp);
	}
	if (c == 'I') {
		vector<node*> icp = is;
		is.clear();
		update_list(icp);
	}
	if (c == 'T') {
		vector<node*> tcp = ts;
		ts.clear();
		update_list(tcp);
	}
}
 
void solve(vector<char> & c, node * n) {
	if (n->kids.size() == 0) {
		c.emplace_back(n->c);
		return;
	}
	for (auto kid : n->kids) {
		solve(c, kid);
	}
}
 
 
int main() {
	int n; cin >>n;
	node * root = new node();
	expand(root);
	for (int i = 0; i < n; i++) {
		char c; cin>>c;
		expand_char(c);
	}
	vector<char> c;
	solve(c, root);
	for (auto ch : c) cout << ch;
}
 
 
 
/*
int main() {
	int n; cin >>n;
	int hc = 0;
	int ic = 0;
	int tc = 0;
	vector<char> v;
	vector<int> hnext(n);
	vector<int> inext(n);
	vector<int> tnext(n);
	for (int i = 0; i < n; i++) {
		char c; cin >> c;
		v.emplace_back(c);
	}
	int hprev = n;
	int iprev = n;
	int tprev = n;
	for (int i = n-1; i >= 0; i--) {
		if (v[i] == 'H') hprev = i;
		if (v[i] == 'I') iprev = i;
		if (v[i] == 'T') tprev = i;
	}
 
}
*/
 
 
 
 
 
 

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED