下图为n = 5时输出的图案,输入一个正整数n,输出一个n+1行特殊的直角三角形,则①处应补充的代码为?
int n;
cin >> n;
cout << "*" << endl;
for (int i = 1; i <= n; i++){
for (int j = 1; _①_; j++){
cout << "*";
}
cout << endl;
}
j <= 2 * i
j <= i
j <= 2 * i - 1
j <= 2 * i + 1