PTA(Advanced Level)1031.Hello World for U

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

思路

• 要使得图像尽可能像正方形，且底部边长要\(\ge\)两边边长，由\(n_1+n_2+n_3-2 =N\)可知\(n_1,n_3\)要较小，极限情况是\(n_1=n_2=n_3\)，那么如何保证\(n_1=n_3\le n_2\)呢，让\(n_1=n_3=(n+2)/2\)，因为是向下取整的关系，所以一定会有\(n_1=n_3\le n_2\)成立

代码

#include<bits/stdc++.h>
using namespace std;

int main()
{
	string s;
	cin >> s;
	int n = s.size();
	int vertical, bottom;
	vertical = (n + 2) / 3;
	bottom = n - 2*vertical + 2;

	int l = 0, r = n - 1;
	for(int i=0;i<vertical-1;i++)
	{
		cout << s[l];
		for(int j=0;j<bottom-2;j++)	cout << " ";
		cout << s[r];
		cout << endl;
		l++; r--;
	}
	for(int i=l;i<=r;i++)
		cout << s[i];
	return 0;
}

引用

https://pintia.cn/problem-sets/994805342720868352/problems/994805462535356416