AC

Author: izardi

PAT (Advanced Level) Practice/1143 Lowest Common Ancestor （30 point(s)）.cpp

@@ -0,0 +1,32 @@
+#include <cstdio>
+#include <map>
+using namespace std;
+int main(){
+    int M, N;
+    map<int, bool> mp;
+    int data[10005] = {0};
+    scanf("%d %d", &M, &N);
+    for(int i = 0; i < N; ++i){
+        scanf("%d", &data[i]);
+        mp[data[i]] = true;
+    }
+    int u, v, a;
+    for(int i = 0; i < M; ++i){
+        scanf("%d %d", &u, &v);
+
+        for(int j = 0; j < N; ++j){
+            a = data[j];
+            if((a >= u && a <= v) || (a <= u && a >= v))
+                break;
+        }
+        if(mp[u] == 0 && mp[v] == 0)
+            printf("ERROR: %d and %d are not found.\n", u, v);
+        else if(mp[u] == false || mp[v] == false)
+            printf("ERROR: %d is not found.\n", mp[u] == false ? u : v);
+        else if(a == u || a == v)
+            printf("%d is an ancestor of %d.\n", a, a == u ? v : u);
+        else
+            printf("LCA of %d and %d is %d.\n", u, v, a);
+    }
+    return 0;
+}