[PAT (Advanced Level) ]1031.Hello World for U 解题文档

1031. Hello World for U (20)

时间限制

400 ms

内存限制

65536 kB

代码长度限制

16000 B

判题程序

Standard

作者

CHEN, Yue

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  de  ll  rlowo

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   dl   llowor

分析：此题难度很小，估计是PAT甲级里面难度系数垫底的题目了，一遍过。需要讨论三种情况。求出n1,n2,n3后输出即可。

C++代码如下。

#include<string>#include<iostream>using namespace std;int main(){    string str;    cin>>str;    int N;    int n1,n2;//n3=n1    N=str.size();    //three conditions    if((N+2)%3==0){        n1=(N+2)/3;        n2=n1;    }    else if((N+2)%3==1){        n1=(N+1)/3;        n2=n1+1;    }    else if((N+2)%3==2){        n1=N/3;        n2=n1+2;    }    for(int i=0;i<n1-1;i++){        cout<<str[i];        for(int j=0;j<n2-2;j++)            cout<<" ";        cout<<str[N-i-1]<<endl;    }    cout<<str.substr(n1-1,n2);    return 0;}