1.题目要求把一个字符串按照U型输出。
2..通过 n1 = n3 = max { k| k <= n2 for all 3 <= n2 <= N } with n1 + n2 + n3 – 2 = N的条件，通过for循环求出最大的n1。
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 n1characters, 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
AC代码：
//#include<string>
//#include <iomanip>
#include<vector>
#include <algorithm>
//#include<stack>
#include<set>
#include<queue>
#include<map>
//#include<unordered_set>
//#include<unordered_map>
//#include <sstream>
//#include "func.h"
//#include <list>
#include<stdio.h>
#include<iostream>
#include<string>
#include<memory.h>
#include<limits.h>
using namespace std;
int main(void)
{
string s;
cin >> s;
int n = s.size();
int n1 = 0, n2 = 0;
for (int i = 0; i < n; i++)
{//求出n1的最大值
n1 = i;
n2 = n + 2 - 2 * n1;
if (n2 < n1) break;
}
if (n2 < n1)
n1--;
n2 = n + 2 - 2 * n1;
string mid = "";
for (int i = 0; i < n2 - 2; i++)
mid += " ";
for (int i = 0; i < n1 - 1; i++)
{
cout << s[i] << mid << s[s.size() - 1 - i] << endl;
}
for (int i = n1 - 1; i < n1 - 1 + n2; i++)
{
cout << s[i];
}
cout << endl;
return 0;
}