下⾯C++代码以递归⽅式实现字符串反序 ,横线处应填上代码是( )。

sIn[sIn.length() - 1] + sReverse(sIn .substr(0, sIn.length() - 1));
sIn[0] + sReverse(sIn .substr(1, sIn.length() - 1));
sReverse(sIn .substr(0, sIn.length() - 1)) + sIn[sIn.length() - 1];
sReverse(sIn .substr(1, sIn.length() - 1)) + sIn[sIn.length() - 1];
发表评论