1031. Hello World for U (20)

Given any string of N (>=5) characters, you are asked to form the characters into the shape of U. For example, "helloworld" can be printed as:

h  d
e  l
l  r
lowo

That is, the characters must be printed in the original order, starting top-down from the left vertical
line with n1 characters,
then left to right along the bottom line with n2 characters,
and finally bottom-up along the vertical line with n3 characters.
And more, we would like U to be as squared as possible -- that is, it must be satisfied that n1 =
n3 =
max { k| k <= n2 for
all 3 <= n2 <=
N } with n1 +
n2 +
n3 -
2 = N.

Input Specification:

Each input file contains one test case. Each case contains one string with no less than 5 and no more than 80 characters in a line. The string contains no white space.

Output Specification:

For each test case, print the input string in the shape of U as specified in the description.
Sample Input:

helloworld!

Sample Output:

h   !
e   d
l   l
lowor

简析：一次ac，不解释。

#include <iostream>
using namespace std;

int main(int argc, const char * argv[]) {
string s;
cin >> s;
int len = (int)s.length();
int n1, n2, n3, i = 0;
n1 = n3 = (len + 2) / 3;
n2 = len - n1 * 2 + 2;

for (i = 0; i < n1 - 1; i++) {
for (int j = 0; j < n2; j++) {
if (j == 0) {
printf("%c", s[i]);
}else if(j == n2 - 1){
printf("%c\n", s[len - i - 1]);
}else{
printf(" ");
}
}
}
int t = i;
for (; i < t + n2; i++) {
printf("%c", s[i]);
}
printf("\n");

return 0;
}