Add 06890.cpp

Author: Hiyabye

06xxx/06890.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+#include <string>
+using namespace std;
+
+inline int c2i(char c) { return c - 'A'; }
+inline char i2c(int i) { return i + 'A'; }
+
+inline char calc(char a, char b) {
+  return i2c((c2i(a) + c2i(b)) % 26);
+}
+
+void solve(void) {
+  string a; getline(cin, a);
+  string b; getline(cin, b);
+  
+  for (int i=0; i<b.length(); i++) {
+    if ('A' <= b[i] && b[i] <= 'Z') continue;
+    b.erase(i--, 1);
+  }
+
+  for (int i=0; i<b.length(); i++) {
+    cout << calc(b[i], a[i % a.length()]);
+  }
+}
+
+int main(void) {
+  ios::sync_with_stdio(false);
+  cin.tie(nullptr);
+
+  solve();
+  return 0;
+}