UVA400 Unix Is

<pre name="code" class="cpp">#include<iostream>#include<string>#include<algorithm>using namespace std;const int maxcol = 60;const int maxn = 100 + 5;string filenames[maxn];//字符数组，里面存的就是文件名//输出字符串s，长度不足len时补字符extravoid print(const string& s,int len, char extra) {    cout << s;    for(int i = 0; i < len-s.length(); i++)        cout << extra;}int main(){    int n;    while(cin >> n) {        int M = 0;        for(int i = 0; i < n; i++) {            cin >> filenames[i];            M = max(M, (int)filenames[i].length());//这一步可以找出最长的文件名        }        int cols = (maxcol - M) / (M + 2) + 1, rows = (n - 1) / cols + 1;        //  求出列数cols和行数rows        print("", 60, '-');        cout << "\n";        sort(filenames, filenames+n);//按ASCII码排序        for(int r = 0; r < rows; r++) {            for(int c = 0; c < cols; c++) {                int idx = c * rows + r;                if(idx < n) print(filenames[idx], c == cols - 1 ? M : M+2, ' ');//输出            }            cout << "\n";        }    }    return 0;}