백준 4158번 CD C++

출처 : https://www.acmicpc.net/problem/4158

 

투 포인터를 활용해서 문제를 해결하였다.

 

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <algorithm>
#include <utility>
#include <stack>
#include <queue>
#include <math.h>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>

using namespace std;
using ll = long long;

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	int n, m;
	while (true) {
		cin >> n >> m;
		if (n == 0 && m == 0) break;
		vector<int> v1(n);
		vector<int> v2(m);
		for (int i = 0; i < n; i++) {
			cin >> v1[i];
		}
		for (int i = 0; i < m; i++) {
			cin >> v2[i];
		}
		int p1 = 0;
		int p2 = 0;
		int cnt = 0;
		while (true) {
			if (p1 == n - 1 && p2 == m - 1) {
				if (v1[p1] == v2[p2]) cnt++;
				break;
			}
			if (p1 == n - 1) {
				if (v1[p1] == v2[p2]) cnt++;
				p2++;
				continue;
			}
			if (p2 == m - 1) {
				if (v1[p1] == v2[p2]) cnt++;
				p1++;
				continue;
			}
			if (v1[p1] == v2[p2]) {
				cnt++;
				p1++;
				p2++;
			}
			else if (v1[p1] > v2[p2]) p2++;
			else p1++;
		}
		cout << cnt << "\n";
	}
};