Question

我的任务是读取一个包含游戏名称和分数的文件（文件看起来像）

5
John Doe 200
Chris Brown 340
Chris Brown 320
John Smith 300
John Doe 600

并按字母顺序（姓氏）打印出该人的最高分数。因此输出看起来像：

Chris Brown 340
John Doe 600
John Smith 300

我想出了如何从最高到最低分类和打印分数，但我却失去了如何打印出每个人的最高分......任何帮助都会受到赞赏！

#include <iostream>
#include <fstream>
using namespace std;

struct playerscore
{
    string first, last;
    int score;
};

bool score(playerscore a, playerscore b);
void selectionsort(playerscore *A, int n);

int main()
{
    string file;
    int n;
    cin >> file;
    ifstream fin(file.c_str());
    fin >> n;

    // read in the names and the scores in the form of struct playerscore
   playerscore *A = new playerscore[n];
    for(int i = 0; i < n; i++)
        fin >> A[i].first >> A[i].last >> A[i].score;

    // sort the data
    selectionsort(A, n);

    // print in sorted order
    for(int i = 0; i < n; i++)
        cout << A[i].score << " ";
    cout << endl;

    return 0;
}

bool before(playerscore a, playerscore b)
{
    return a.score > b.score;
}
void selectionsort(playerscore *A, int n)
{
    for(int length = n; length > 1; length--)
    {
        //find imax, index of largest
        int imax = 0, i;
        for(i = 1; i < length; i++)
            if(before(A[imax], A[i]))
                imax = i;
        // swap A[imax] and the last element
        playerscore temp = A[imax];
        A[imax] = A[length-1];
        A[length-1] = temp;
    }
}

Answer 1

如前所述，由于这是一项任务，我决定重写代码，现在看起来应该是这样。

根据分数对数组进行排序
根据字母顺序对数组进行排序

打印唯一条目

#include <iostream>
#include <fstream>
using namespace std;

struct playerscore
{
    string first, last;
    int score;
};

bool score(playerscore a, playerscore b);
void selectionsort(playerscore *A, int n);

int main()
{
    string file;
    int n;
    cin >> file;
    ifstream fin(file.c_str());
    fin >> n;

    // read in the names and the scores in the form of struct playerscore
    playerscore *A = new playerscore[n];
    for (int i = 0; i < n; i++)
        fin >> A[i].first >> A[i].last >> A[i].score;

    // sort the data
    selectionsort(A, n);
    // sort alphabetically and print unique entries
    for (int i=0; i<n-1; i++)
    {
        for (int j=i+1; j<n; j++)
        {
            if (A[j].last <= A[i].last && A[j].first < A[i].first)
            {
                playerscore tmp = A[i];
                A[i] = A[j], A[j] = tmp;
            }
     }

     playerscore max;
     int j = 0;
     for (int i=0; j+i<n; i++)
     {
         max.score = -1;

         while (j+i<n && A[j+i].last == A[i].last && A[j+i].first == A[i].first)
         {
             if (A[j+i].score >= A[i].score)
                 max = A[j+i];
             j++;
         }
         j--;

         if (max.score >= 0)
             cout << max.last << " " << max.first << " " << max.score << endl;
     }
     cout << endl;

     return 0;
 }

 bool before(playerscore a, playerscore b)
 {
      return a.score > b.score;
 }

 void selectionsort(playerscore *A, int n)
 {
     for(int length = n; length > 1; length--)
     {
         //find imax, index of largest
         int imax = 0, i;
         for(i = 1; i < length; i++)
             if(before(A[imax], A[i]))
                 imax = i;
         // swap A[imax] and the last element
         playerscore temp = A[imax];
         A[imax] = A[length-1];
         A[length-1] = temp;
     }
 }

Answer 2

按名称的升序排序。如果比较的名称相同，则得分较高的元素应该到达数组的较早位置。
打印名称与上一个元素不同的第一个元素和元素。

示例实施：

#include <iostream>
#include <fstream>
using namespace std;

struct playerscore
{
    string first, last;
    int score;
};

bool score(playerscore a, playerscore b);
void selectionsort(playerscore *A, int n);

int main()
{
    string file;
    int n;
#if 0
    cin >> file;
    ifstream fin(file.c_str());
#else
#define fin cin // to test with online compiler
#endif
    fin >> n;

    // read in the names and the scores in the form of struct playerscore
   playerscore *A = new playerscore[n];
    for(int i = 0; i < n; i++)
        fin >> A[i].first >> A[i].last >> A[i].score;

    // sort the data
    selectionsort(A, n);

    // print in sorted order
    for(int i = 0; i < n; i++)
        if (i == 0 || A[i].first != A[i - 1].first || A[i].last != A[i - 1].last)
            cout << A[i].first << " " << A[i].last << " " << A[i].score << "\n";
    cout << endl;

    return 0;
}

bool before(playerscore a, playerscore b)
{
    return a.first == b.first ? (a.last == b.last ? a.score > b.score : a.last < b.last) : a.first < b.first;
}
void selectionsort(playerscore *A, int n)
{
    for(int length = n; length > 1; length--)
    {
        //find imax, index of largest
        int imax = 0, i;
        for(i = 1; i < length; i++)
            if(before(A[imax], A[i]))
                imax = i;
        // swap A[imax] and the last element
        playerscore temp = A[imax];
        A[imax] = A[length-1];
        A[length-1] = temp;
    }
}

Answer 3

你已经完成了困难的部分。

假设((first, last), score)对已经排序，每个玩家的最高得分是该玩家的第一个记录，因此当您访问该玩家时，请将当前玩家的名称保持为curr_name阵列：

如果下一个名称与curr_name相同，则可以放心地忽略此项目。
如果没有，请打印此记录，然后更新curr_name。

代码就像吹：

#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <string>
#include <utility>
using namespace std;
bool mycmp (pair<pair<string, string>, int> a, pair<pair<string, string>, int> b) {
    return a.first < b.first || (a.first == b.first && a.second > b.second);
}
int main(int argc, char *argv[])
{
    ifstream fin("data.txt");
    int n;
    fin>>n;
    vector<pair<pair<string, string>, int>> A(n);
    for(int i = 0; i < n; ++i){
        fin>>A[i].first.first>>A[i].first.second>>A[i].second;
    }
    sort(A.begin(), A.end(), mycmp);
    pair<string, string> cur_name;
    for(int i = 0; i < n; ++i){
        if(cur_name != A[i].first){
            cout<<A[i].first.first<<" "<<A[i].first.second<<" "<<A[i].second<<endl;
            cur_name = A[i].first;
        }
    }
    return 0;
}

排序结构和数组

3 个答案: