PAT_A 1031 Hello World for U

PAT_A 1031 Hello World for U

分析

按照题目要求进行处理即可，即将原字符串（长度为N）按U型输出。n1=n3为高，n2为宽，且n1<=n2-1，3<=n2<=N；这里的n1比题中的n1小一，原因是题中的n1加上了与n2的交点。

题目的描述

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=ma**x { 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的代码

#include<bits/stdc++.h>

using namespace std;

int main(){
    string s;
    cin>>s;
    int n1=0,n2=0;
    int N = s.length();
    n2 = N/3;
    if(n2<3)n2=3;
    n1 = (N-n2)/2;
    while(n1>n2-1){
        n1-=1;
        n2+=2;
    }
    n2+=N-(2*n1+n2);
    for(int i=0;i<n1;i++){
        string t(n2,' ');
        t[0]=s[i];t[n2-1]=s[N-1-i];
        cout<<t<<endl;
    }
    cout<<s.substr(n1,n2)<<endl;
    return 0;
}