feat: solved 숫자카드 2 / binary serach with lower&upper bound

jiyunpar/binary_search/10816.cpp

@@ -0,0 +1,64 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <string>
+
+using namespace std;
+
+
+int n, m;
+vector<int> seq;
+vector<int> target;
+
+int	upperbound(int val)
+{
+	int st = 0;
+	int end = n;
+	while (st < end)
+	{
+		int mid = (st + end) / 2;
+		if (seq[mid] > val)
+			end = mid;
+		else
+			st = mid + 1;
+	}
+	return (st);
+}
+
+int	lowerbound(int val)
+{
+	int st = 0;
+	int end = n;
+	while (st < end)
+	{
+		int mid = (st + end) / 2;
+		if (seq[mid] >= val)
+			end = mid;
+		else
+			st = mid + 1;
+	}
+	return (st);
+}
+
+int main(void)
+{
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+	seq.reserve(500000);
+	cin >> n;
+	for (int i = 0; i < n; ++i)
+	{
+		int val;
+		cin >> val;
+		seq.push_back(val);
+	}
+	sort(seq.begin(), seq.end());
+	cin >> m;
+	while (m--)
+	{
+		int val;
+		cin >> val;
+		cout << upperbound(val) - lowerbound(val) << " ";	
+	}
+	return (0);
+}

jiyunpar/binary_search/10816_1.cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <string>
+
+using namespace std;
+
+
+int n, m;
+vector<int> seq;
+vector<int> target;
+
+// using STL lowerbound upperbound
+// return val : if array -> pointer
+//				if stl container -> iterator
+
+int main(void)
+{
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+	seq.reserve(500000);
+	cin >> n;
+	for (int i = 0; i < n; ++i)
+	{
+		int val;
+		cin >> val;
+		seq.push_back(val);
+	}
+	sort(seq.begin(), seq.end());
+	cin >> m;
+	while (m--)
+	{
+		int val;
+		cin >> val;
+		cout << upper_bound(seq.begin(), seq.end(), val) - lower_bound(seq.begin(), seq.end(), val) << " ";	
+	}
+	return (0);
+}