'commit'

TangDou/XiTi/1319.cpp

@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    int n;
+    int sum = 0;
+    int pre = 0;
+    while (cin >> n) {
+        if (n == 0) break;
+        if (n == 1) {
+            sum++;
+            pre = 0;
+        }
+        if (n == 2) {
+            pre += 2;
+            sum += pre;
+        }
+    }
+    cout << sum << endl;
+    return 0;
+}