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我正在尝试编写一个简单的程序来使用欧拉方法计算数值近似值,而我使用的每个编译器都没有打印任何内容。Codeblocks 运行错误,但我认为这是因为编译器设置不正确。xCode 将构建它,但没有任何反应。当我运行 g++ Euler.cpp 时,我得到:

Euler.cpp:1: error: expected constructor, destructor, or type conversion before ‘<’ token
Euler.cpp: In function ‘int main()’:
Euler.cpp:13: error: ‘cin’ was not declared in this scope
Euler.cpp:19: error: ‘cout’ was not declared in this scope
Euler.cpp:19: error: ‘endl’ was not declared in this scope

我通常不会遇到简单的 C++ 程序的问题,并且担心这是非常明显的事情。

//
//  Euler.cpp
//  Numerical Approximations (Euler's Method)
//
//  Created by XXXXXXXXXXXX on 6/18/12.
//  Copyright (c) 2012 University of Kansas Department of Mathematics. All rights     reserved.
//

#include <iostream>
using namespace std;

int main ()
{

    int N=4;
    //cout<<"Number of steps (N):";
    //cin>>t;

    float h=0.1;
    //cout<<endl<<" Step size (h):";
    cin>>h;

    float y0=1;
    //cout<<endl<<"y(0)=";
    //cin>>y0;

    cout<<"test!"<<endl;

    float data[N][4];

    int n=0;

    data[0][2] = y0;

    while (n<N){
        data[n][0]=n;
        if(n>0){
             data[n][2]=data[n-1][3];
        }
        data[n][1]=h*n;
        data[n][3] = data[n][2] + ((3 + data[n][1] - data[n][2])*h);
        n++;
        cout<<"n="<<n<<". tn="<<data[n][1]<<". y(n)="<<data[n][2]<<". y(n+1)="<<data[n][3] <<"."<<endl;
    }




 return 0;
 }

这可能是显而易见的,但我没有看到。

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1 回答 1

2

它没有找到 iostream 标头。您是否看到类似“找不到标头 iostream”的错误消息?

于 2012-06-18T23:55:11.940 回答