注意一下n1和n2的计算
#include<iostream>
#include<string>
using namespace std;
string s;
int main()
{
getline(cin, s);
int len = s.length();
int n1 = (len+2) / 3;
int n2 = len - 2 * n1;
for (int i = 0; i < n1-1; i++)
{
printf("%c", s[i]);
for (int k = n2; k >0; k--)printf(" ");
printf("%c", s[len - 1 - i]);
printf("\n");
}
for (int i = n1 - 1; i <= n1 + n2; i++)printf("%c", s[i]);
return 0;
}