| Time Limit: 1000MS | Memory Limit: 10000K | |
| Total Submissions: 2876 | Accepted: 967 |
Description
The computer company you work for is introducing a brand new computer line and is developing a new Unix-like operating system to be introduced along with the new computer. Your assignment is to write the formatter for the ls function.
Your program will eventually read input from a pipe (although for now your program will read from the input). Input to your program will consist of a list of (F) filenames that you will sort (ascending based on the ASCII character values) and format into (C) columns based on the length (L) of the longest filename. Filenames will be between 1 and 60 (inclusive) characters in length and will be formatted into left-justified columns. The rightmost column will be the width of the longest filename and all other columns will be the width of the longest filename plus 2. There will be as many columns as will fit in 60 characters. Your program should use as few rows (R) as possible with rows being filled to capacity from left to right.
Input
The input will contain an indefinite number of lists of filenames. Each list will begin with a line containing a single integer (1 <= N <= 100). There will then be N lines each containing one left-justified filename and the entire line's contents (between 1 and 60 characters) are considered to be part of the filename. Allowable characters are alphanumeric (a to z, A to Z, and 0 to 9) and from the following set { ._- } (not including the curly braces). There will be no illegal characters in any of the filenames and no line will be completely empty.
Immediately following the last filename will be the N for the next set or the end of file. You should read and format all sets in the input.
Output
For each set of filenames you should print a line of exactly 60 dashes (-) followed by the formatted columns of filenames. The sorted filenames 1 to R will be listed down column 1; filenames R+1 to 2R listed down column 2; etc.
Sample Input
10 tiny 2short4me very_long_file_name shorter size-1 size2 size3 much_longer_name 12345678.123 mid_size_name 12 Weaser Alfalfa Stimey Buckwheat Porky Joe Darla Cotton Butch Froggy Mrs_Crabapple P.D. 19 Mr._French Jody Buffy Sissy Keith Danny Lori Chris Shirley Marsha Jan Cindy Carol Mike Greg Peter Bobby Alice Ruben
Sample Output
------------------------------------------------------------ 12345678.123 size-1 2short4me size2 mid_size_name size3 much_longer_name tiny shorter very_long_file_name ------------------------------------------------------------ Alfalfa Cotton Joe Porky Buckwheat Darla Mrs_Crabapple Stimey Butch Froggy P.D. Weaser ------------------------------------------------------------ Alice Chris Jan Marsha Ruben Bobby Cindy Jody Mike Shirley Buffy Danny Keith Mr._French Sissy Carol Greg Lori Peter
Source
Regionals 1995 >> North America - South Central USA
問題鏈接：POJ1589 ZOJ1324 UVA400 UVALive5484 Unix ls
問題描述：（略）
問題分析：
在文本界面時代，一個目錄下的目錄和文件需要顯示，並且按照一定的格式進行顯示。這個題就是解決這樣的問題的。
需要顯示的文件名需要排序一下。
這個題的關鍵是計算總共的行數和列數，本來需要考慮能否整除的問題，如果用條件判斷來做邏輯清晰，但是描述繁瑣，找出一個計算公式來並且用一個表達式來描述計算就簡潔了。
程序說明：
這個程序在ZOJ1324中出現PE，只能說ZOJ的測試數據與衆不同，也許是考慮了特殊的情況？
參考鏈接：（略）
題記：用表達式描述一個計算是最簡潔的方式。
AC的C++語言程序(ZOJ1324中PE)如下：
/* POJ1589 ZOJ1324 UVA400 UVALive5484 Unix ls */
#include <iostream>
#include <algorithm>
using namespace std;
const int COL = 60;
const int N = 100;
string fn[N];
// 輸出字符串s，補足空格使之長度爲len
void print(const string& s, int len, char extra)
{
cout << s;
len -= s.length();
while(len--)
cout << extra;
}
int main()
{
int n;
while(cin >> n) {
int maxlen = 0;
for(int i = 0; i < n; i++) {
cin >> fn[i];
maxlen = max(maxlen, (int)fn[i].length());
}
// 計算行數rows和列數cols
int cols = (COL - maxlen) / (maxlen + 2) + 1;
int rows = (n - 1) / cols + 1;
// 輸出結果：先按字典順序排序
sort(fn, fn + n);
print("", COL, '-');
cout << endl;
for(int i = 0; i < rows; i++) {
for(int j = 0; j < cols; j++) {
int idx = j * rows + i;
if(idx < n)
print(fn[idx], j == cols - 1 ? maxlen : maxlen + 2, ' ');
else
break;
}
cout << endl;
}
}
return 0;
}