'commit'

TangDou/ShuLun/SL_18.cpp

@@ -0,0 +1,17 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+//给出等差数列的前两项，分别是a1,a2,问第n项是多少
+int x, y, n;
+
+int main() {
+    cin >> x >> y >> n;
+    int z = y - x;
+    if (n == 1) cout << x << endl;
+    if (n == 2) cout << y << endl;
+    if (n >= 3) {
+        for (int i = 3; i <= n; i++)y += z;
+        cout << x << endl;
+    }
+    return 0;
+}