c++ - 为什么在clrscr()中出错？它说未定义？

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“UNDEFINED REFRENCE TO clrscr();” [duplicate]
                                
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#include<iostream>
using namespace std;
#include<conio.h>

#include<stdio.h>

class cpuschedule
{
    int n, bu[20];

    float twt, awt, wt[20], tat[20];

public:

    void Getdata();

    void fcfs();

    void sjf();

    void roundrobin();

};

//Getting no of processes and Burst time

void cpuschedule::Getdata()
{
    int i;

    cout << "Enter the no of processes : ";

    cin >> n;

    for (i = 1; i <= n; i++)
    {
        cout << "\nEnter The BurstTime for Process p"<< i << " = ";

        cin >> bu[i];
    }

}

//First come First served Algorithm

void cpuschedule::fcfs()
{
    int i, b[10];

    float sum = 0.0;

    twt = 0.0;

    for (i = 1; i <= n; i++)
    {
        b[i] = bu[i];

        cout << "\nBurst time for process p"<< i << " = ";

        cout << b[i];
    }

    wt[1] = 0;

    for (i = 2; i <= n; i++)
    {
        wt[i] = b[i - 1] + wt[i - 1];
    }

    for (i = 1; i <= n; i++)
    {
        twt = twt + wt[i];

        tat[i] = b[i] + wt[i];

        sum += tat[i];
    }

    awt = twt / n;
    sum = sum / n;

    cout << "\nTotal Waiting Time = " << twt;

    cout << "\nAverage Waiting Time = " << awt;

    cout << "\nAverage Turnaround time = " << sum;

}

//Shortest job First Algorithm

void cpuschedule::sjf()
{

    int i, j, temp, b[10];

    float sum = 0.0;

    twt = 0.0;

    for (i = 1; i <= n; i++)
    {
        b[i] = bu[i];

        cout << "\nBurst time for process p" << i << " = ";

        cout << b[i];
    }

    for (i = n; i >= 1; i-)
    {
        for (j = 2; j <= n; j++)
        {
            if (b[j - 1]>b[j])
            {
                temp = b[j - 1];

                b[j - 1] = b[j];

                b[j] = temp;
            }
        }
    }

    wt[1] = 0;

    for (i = 2; i <= n; i++)
    {
        wt[i] = b[i - 1] + wt[i - 1];
    }

    for (i = 1; i <= n; i++)
    {
        twt = twt + wt[i];

        tat[i] = b[i] + wt[i];

        sum += tat[i];
    }

    awt = twt / n;
    sum = sum / n;

    cout << "\nTotal Waiting Time = " << twt;

    cout << "\nAverage Waiting Time = " << awt;

    cout << "\nAverage turnaround time = " << sum;
}

//Round Robin Algorithm

void cpuschedule::roundrobin()
{
    int i, j, tq, k, b[10], Rrobin[10][10], count[10];

    int max = 0;

    int m;

    float sum = 0.0;

    twt = 0.0;

    for (i = 1; i <= n; i++)
    {
        b[i] = bu[i];

        cout << "\nBurst time for process p" << i << " = ";

        cout << b[i];

        if (max<b[i])

            max = b[i];

        wt[i] = 0;
    }

    cout << "\nEnter the Time Quantum = ";

    cin >> tq;

    //TO find the dimension of the Round robin array

    m = max / tq + 1;

    //initializing Round robin array

    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= m; j++)
        {
            Rrobin[i][j] = 0;
        }
    }

    //placing value in the Rrobin array

    i = 1;

    while (i <= n)
    {
        j = 1;

        while (b[i]>0)
        {
            if (b[i] >= tq)
            {
                b[i] = b[i] - tq;

                Rrobin[i][j] = tq;

                j++;
            }
            else
            {
                Rrobin[i][j] = b[i];

                b[i] = 0;

                j++;
            }
        }

        count[i] = j - 1;

        i++;
    }

    cout <<" Display";

    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= m; j++)
        {
            cout << "\nRr[" << i << ", " << j << "] = " << Rrobin[i][j];

            cout << "     ";
        }
        cout << "\ncount = " << count[i];
    }

    for (j = 1; j <= n; j++)
    {
        for (i = 1; i <= count[j]; i++)
        {
            if (i == count[j])
            {
                for (k = 1; k<j; k++)
                {
                    if (k != j)

                        wt[j] += Rrobin[k][i];
                }
            }

            else

            for (k = 1; k <= n; k++)
            {

                if (k != j)

                    wt[j] += Rrobin[k][i];
            }
        }
    }

    for (i = 1; i <= n; i++)
        cout << "\nWaiting Time for process P" << i << " = " << wt[i];

    //calculating Average Weighting Time

    for (i = 1; i <= n; i++)
    {
        twt = twt + wt[i];

        tat[i] = b[i] + wt[i];

        sum += tat[i];
    }

    awt = twt / n;
    sum = sum / n;

    cout << "\nTotal Waiting Time = " << twt;

    cout << "\nAverage Waiting Time = " << awt;

    cout << "\nAverage turnaround time = " << sum;

}

void main()
{
    int ch = 0, cho;

    cpuschedule c;

    clrscr();

    do
    {
        switch (ch)
        {

        case 0:

            cout << "\n0.MENU";

            cout << "\n1.Getting BurstTime";

            cout << "\n2.FirstComeFirstServed";

            cout << "\n3.ShortestJobFirst";

            cout << "\n4.RoundRobin";

            cout << "\n5.EXIT";

            break;

        case 1:
            c.Getdata();
            break;

        case 2:
            cout << "FIRST COME FIRST SERVED SCHEDULING";

            c.fcfs();
            break;

        case 3:
            cout << "SHORTEST JOB FIRST SCHEDULING";
            c.sjf();
            break;

        case 4:
            cout << "ROUND ROBIN SCHEDULING";
            c.roundrobin();
            break;

        case 5:
            break;

        }

        cout << "\nEnter your choice : ";

        cin >> ch;

        getch();

    } while (ch<5);
}

这是编译器错误：


  clrscr未定义

最佳答案

我为您编写了一个小示例。我假设您正在Windows上运行。

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

#include <stdio.h> // include this for the clear

int main()
{
  string usersInput;
  cout <<"Enter string: ";
  getline(cin,usersInput);

  cout << "The string is: " << usersInput << endl;

  cout << "Press Enter to clear screen.";

  cin.ignore();
  system("CLS"); // this clears the screen

  cin.ignore();
  return 0;
}