P1047 [NOIP2005 普及组] 校门外的树

R63269725

Luogu/P1047/P1047.cpp

@@ -0,0 +1,21 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int l, m, u, v, ans;
+bool t[10005];
+
+int main() {
+    cin >> l >> m;
+    for (int i = 0; i < m; i++) {
+        cin >> u >> v;
+        for (int j = u; j <= v; j++) {
+            t[j] = true;
+        }
+    }
+    for (int i = 0; i <= l; i++) {
+        ans += !t[i];
+    }
+    cout << ans << endl;
+    return 0;
+}