'commit'

TangDou/LuoGuBook/P3997_0.cpp

@@ -0,0 +1,17 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+char a[] = {'A', 'B', 'C'};
+int main() {
+    // AB AC BC 要
+    // BA CB CA x
+    for (int i = 0; i < 3; i++)
+        for (int j = 0; j < 3; j++)
+            cout << a[i] << a[j] << " ";
+
+    puts("");
+    for (int i = 0; i < 3; i++)
+        for (int j = i + 1; j < 3; j++)
+            cout << a[i] << a[j] << " ";
+    return 0;
+}