20240426 Create cf1029c_iron_buster.java (Yawn-Sean#1641)

Author: Iron-Buster

daily_problems/2024/04/0426/personal_submission/cf1029c_iron_buster.java

@@ -0,0 +1,47 @@
+public class Main {
+
+    // https://codeforces.com/problemset/problem/1029/C
+    // https://codeforces.com/contest/1029/submission/258176653
+    public static void solve() throws Exception {
+        int n = in.nextInt();
+        var a = new long[n][2];
+        long maxLeft = Long.MIN_VALUE / 2;
+        long minRight = Long.MAX_VALUE / 2;
+        var map1 = new TreeMap<Long, Integer>();
+        var map2 = new TreeMap<Long, Integer>();
+        for (int i = 0; i < n; i++) {
+            long l = in.nextLong();
+            long r = in.nextLong();
+            a[i][0] = l;
+            a[i][1] = r;
+            maxLeft = Math.max(maxLeft, l);
+            minRight = Math.min(minRight, r);
+            map1.merge(l, 1, Integer::sum);
+            map2.merge(r, 1, Integer::sum);
+        }
+        long ans = 0;
+        for (int i = 0; i < n; i++) {
+            long l = a[i][0], r = a[i][1];
+            if (l == maxLeft && map1.get(l) == 1) {
+                map1.remove(l);
+                if (r == minRight && map2.get(r) == 1) {
+                    map2.remove(r);
+                    ans = Math.max(ans, map2.firstKey() - map1.lastKey());
+                    map2.put(r, 1);
+                } else {
+                    ans = Math.max(ans, minRight - map1.lastKey());
+                }
+                map1.put(l, 1);
+            } else {
+                if (r == minRight && map2.get(r) == 1) {
+                    map2.remove(r);
+                    ans = Math.max(ans, map2.firstKey() - maxLeft);
+                    map2.put(r, 1);
+                } else {
+                    ans = Math.max(ans, minRight - maxLeft);
+                }
+            }
+        }
+        out.println(ans);
+    }
+}