大小写转换

J.cpp

@@ -0,0 +1,13 @@
+#include<iostream>
+#include<string>
+using namespace std;
+int main(){
+    string str;
+    while(cin >> str){
+        for(int i = 0; i < str.size(); i++){
+            if('a' <= str[i] && 'z' >= str[i]) str[i] += 'A' - 'a';
+        }
+        cout << str << endl;
+    }
+    return 0;
+}