Question

我在排序char数组时遇到问题。有一个数组2 * 5 3 4应该从文件中排序，但我可以在代码中找到错误。编译器只是读取数组。任何建议，评论

#include <iostream> // cin cout endl
#include <fstream> // ifstream
#include <sstream> // stringstream
#include <stdlib.h> //exit
#include <vector>
#include "insertionSort.h";

using std::cerr;
using std::cout;
using std::endl;
using std::ifstream;
using std::vector;
using namespace std;


const int MAX_CHARS = 200; // max length of each line to read from the input file

template<class T>
void readSortOutput( char* typeName, vector<T> v, ifstream &inStream );

int main( )
{
    int array_size= 1024;
    char *array = new char[array_size];
    int possition;
    ifstream inStream("/home/xx/Downloads/input.txt");
    cout << "Insertion sort algorithm driver program" << endl;

    if( inStream.fail( ) )
    {
        cerr << "Input file opening failed.\n";
        exit(1);
    }
   while (!inStream.eof()&&possition<array_size)
   {
       inStream.get(array[possition]);
       possition++;
   }
   array[possition-1] = '\0';
   cout <<"Display the array" <<endl <<endl;
   for (int i=0;array[i] !='\0';i++)
   {
       cout <<array[i];
   }

    vector<int> intVector;
    readSortOutput( (char*)"int", intVector, inStream );

    vector<double> dblVector;
    readSortOutput( (char*)"double", dblVector, inStream );

    vector<char> chrVector;
    readSortOutput( (char*)"char", chrVector, inStream );

    inStream.close( );

    return 0;
}

template<class T>
void readSortOutput( char* typeName, vector<T> v, ifstream &inStream )
{
    // read a line from the input stream into a stringstream
    char fileLine[MAX_CHARS];
    std::stringstream ss;
    inStream.getline(fileLine, MAX_CHARS);
    ss << fileLine;

    // extract elements of the specified type from the stringstream
    T elem;
       while (ss >> elem) {
        v.push_back( elem );
    }

    cout << endl << typeName << " vector before insertion sort: " << endl;
    for (int i = 0; i < v.size( ); i++)
        cout << v[i] << " ";
    cout << endl;

    insertionSort( v ); // the sort itself

    cout << typeName << " vector after insertion sort: " << endl;
    for (int i = 0; i < v.size( ); i++)
        cout << v[i] << " ";
    cout << endl;

    return;
} // readSortOutput

insertionSort.h

#ifndef INSERTIONSORT_H
#define INSERTIONSORT_H

#include <vector> // vector
#include <iostream> // cin cout endl
#include <fstream> // ifstream
#include <sstream> // stringstream
#include <stdlib.h> //exit

using std::vector;

/*template<class T>
void insertionSort(vector<T>& data); // function replaces the given argument
*/


template<class T>
void insertionSort(vector<T>& data)
{
    for (size_t i = 0; i < data.size( ); i++)
        for (size_t j = i; j < data.size( ); j++)
            if (data[ j ] < data[ i ])
            { // swap values
                T temp = data[ j ];
                data[ j ] = data[ i ];
                data[ i ] = temp;
            }

    return;
}
#endif  // INSERTIONSORT_H

Answer 1

while (!inStream.eof()&&possition<array_size)
   {
       inStream.get(array[possition]);
       possition++;
   }

当您浏览上面的循环时，您正在消耗所有输入。因此，当您致电readSortOutput时，无需阅读任何内容。在尝试再次读取数组之前，您应该使用inStream.seekg(0);重置文件中的位置。

数组可以排序

1 个答案: