數組可以排序

Question

我有一個排序字符數組的問題。有一個數組2 * 5 3 4應該從文件中排序，但我可以在代碼中查找錯誤。編譯器只是讀取數組。任何建議，意見

#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++; 
    } 

當你運行循環以上，你正在消耗所有的輸入。因此，當您撥打readSortOutput時，沒有什麼可以閱讀的。在嘗試再次讀取數組之前，您應該使用inStream.seekg(0);重置文件中的位置。