PAT 1038 体验Python之美

1038. Recover the Smallest Number (30)

时间限制

400 ms

内存限制

32000 kB

代码长度限制

16000 B

判题程序

Standard

作者

CHEN, Yue

Given a collection of number segments, you are supposed to recover the smallest number from them. For example, given {32, 321, 3214, 0229, 87}, we can recover many numbers such like 32-321-3214-0229-87 or 0229-32-87-321-3214 with respect to different orders of combinations of these segments, and the smallest number is 0229-321-3214-32-87.

Input Specification:

Each input file contains one test case. Each case gives a positive integer N (<=10000) followed by N number segments. Each segment contains a non-negative integer of no more than 8 digits. All the numbers in a line are separated by a space.

Output Specification:

For each test case, print the smallest number in one line. Do not output leading zeros.

Sample Input:

5 32 321 3214 0229 87

Sample Output:

22932132143287

我做题都是先用python秒一下，要是超时什么的就换C++了，这题我一看，就写了下面这一行代码：

print int(''.join(sorted(raw_input().split()[1:], lambda s1, s2: cmp(s1+s2, s2+s1))))

是的只有一行！可惜最后一个test还是超时了。于是用C++再写：

#include <set>
#include <sstream>
#include <string>
#include <iostream>
using namespace std;

class mstring : public string {
public:
    inline bool operator<(const string &s) const {
        string tmpa(*this);
        tmpa.append(s);
        string tmpb(s);
        tmpb.append(*this);
        return tmpa.compare(tmpb) < 0;
    }
};

int main() {
    //#pragma warning(disable:4996)
    //freopen("..\advanced-pat-python\test.txt", "r", stdin);
    int N;
    cin >> N;
    set<mstring> nums;
    mstring ms;
    while (N--) {
        cin >> ms;
        nums.insert(ms);
    }
    mstring num;
    set<mstring>::iterator it = nums.begin();
    while (it!=nums.end()) {
        num += *(it++);
    }
    while (!num.empty() && *num.begin()=='0') {
        num.erase(num.begin());
    }
    if (num.empty()) {
        num += '0';
    }
    cout << num << endl;
}

总体来说还是较为简单的，但是没有Python那么爽的一行解决掉了。Python真是神奇的语言啊。