PTA-1031——Hello World for U

题目:

Given any string of N (≥) 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 n​1​​ characters, then left to right along the bottom line with n​2​​ characters, and finally bottom-up along the vertical line with n​3​​ characters. And more, we would like U to be as squared as possible -- that is, it must be satisfied that n​1​​=n​3​​=max { k | k≤n​2​​ for all 3 } with n​1​​+n​2​​+n​3​​−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

分析:

算一下三边的长度即可。

代码:

 1 /*
 2 2n1+n2=N+2
 3 n2=N+2-2n1
 4 n1<=n2
 5 n1<=N+2-2n1
 6 n1<=(N+2)/3
 7 */
 8 #include<iostream>
 9 using namespace std;
10 string s;
11 int n;
12 int n1,n2;
13 int main(){
14     cin>>s;
15     n=s.length();
16     n1=(n+2)/3;
17     n2=n-2*n1+2;
18     for(int i=0;i<n1-1;i++){
19         cout<<s[i];
20         for(int j=0;j<n2-2;j++){
21             cout<<" ";
22         }
23         cout<<s[n-1-i]<<endl;
24     }
25     for(int i=0;i<n2;i++){
26         cout<<s[n1-1+i];
27     }
28     return 0;
29 }