1263. 【例9.7】友好城市

http://ybt.ssoier.cn:8088/statusx.php?runidx=15563557

ybt/1263/1263.cpp

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+#include <algorithm>
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 2e5 + 5;
+
+int n, f[N], ans;
+std::pair<int, int> a[N];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i].first >> a[i].second;
+    }
+
+    std::sort(a + 1, a + n + 1);
+
+    for (int i = 1; i <= n; i++) {
+        f[i] = 1;
+        for (int j = 1; j < i; j++) {
+            if (a[j].second < a[i].second) f[i] = std::max(f[i], f[j] + 1);
+        }
+        ans = std::max(ans, f[i]);
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}