在C中找到一堆数组中的max [英] finding max in bunch of arrays in C

问题描述

我有几个问题. 我有一个包含这些信息的文本文件

I have couple of questions. I have a text file which contains these information

x0,x1,y0,y1
142,310,0,959
299,467,0,959
456,639,0,959
628,796,0,959

1. 首先，我想使用fscanf读取文本文件，并通过跳过第一行将数字仅分成4个数组，分别为c1，c2，c3和c4.所以最终结果将是

1. First, I want to read the text file using fscanf and get only the numbers into 4 arrays, c1, c2, c3, and c4 by skipping the first line. So the final result will be

c[1] = {142, 310, 0, 959}
c[2] = {299, 467, 0, 959}
c[3] = {456, 639, 0, 959}
c[4] = {628, 796, 0, 959}

然后，对于每个c[1]至c[4]，我想找到最大整数并将其存储在[x，y]数据类型中.因此，例如在c[1]中，最大值将为max[1] = [310，959].

Then, for each c[1] to c[4], I want to find the maximum integer and store it in [x, y] datatype. So for example in c[1], the max will be max[1] = [310, 959].

任何人都可以帮忙吗?除使用数组解决此问题外，其他C解决方案也将受到欢迎.

Can anyone help? Other C solution other than using arrays to solve this problem is welcome as well.

在matlab中，代码为

In matlab, the code is

fid = fopen('foo.txt','r');
c = textscan(fid,'%d%d%d%d','delimiter',',','headerlines',1);
fclose(fid);

这将简单地忽略第一行，然后将其余数字复制到matlab中的数组中. 我想将此代码转换为C. 非常感谢.

This will simply ignore the first line, then copy rest of numbers into arrays in matlab. I would like to translate this code into C. Thank you very much.

推荐答案

尽管没有直接满足您的问题，但我提供了使用struct，std::istream和std::vector的阅读要点示例.这些优先于fscanf和数组.

Although not satsifying your question directly, I have provided an example of reading points using a struct, std::istream and std::vector. These are preferred over fscanf and arrays.

struct Point
{
  unsigned int x;
  unsigned int y;

  friend std::istream& operator>>(std::istream& inp, Point& p);
};

std::istream& operator>>(std::istream& inp, Point& p)
{
  inp >> p.x;
  //Insert code here to read the separator character(s)
  inp >> p.y;
  return inp;
}

void Read_Points(std::istream& input, std::vector<Point>& container)
{
  // Ignore the first line.
  inp.ignore(1024, '\n');

  // Read in the points
  Point p;
  while (inp >> p)
  {
     container.push_back(p);
  }
  return;
}

由于您可以使用Point声明其他类，所以Point结构提供了更高的可读性，恕我直言，还具有更多的通用性:

The Point structure provides more readability, and IMHO, more versatility because you can declare other classes using a Point:

class Line
{
  Point start;
  Point end;
};

class Rectangle
{
  Point upper_left_corner;
  Point lower_right_corner;
  friend std::istream& operator>>(std::istream& inp, Rectangle& r);
};

您可以使用operator>>来添加用于读取文件的方法:

You can add methods for reading from a file using the operator>> for point:

std::istream& operator>> (std::istream& input, Rectangle& r)
{
  inp >> r.upper_left_corner;
  //Insert code here to read the separator character(s)
  inp >> r.lower_left_corner;
  return inp;
}

数组是一个问题，可能导致讨厌的运行时错误，例如缓冲区溢出.对数组执行std::vector，类或结构.

Arrays are a problem and can lead to nasty runtime errors such as buffer overruns. Perfer std::vector, classes or structures to arrays.

此外，由于使用了std::istream，因此这些结构和类可以轻松地用于std::cin和文件(std::ifstream):

Also, since std::istream is used, these structures and classes can be easily used with std::cin and files (std::ifstream):

  // Input from console
  Rectangle r;
  std::cin >> r;

这篇关于在C中找到一堆数组中的max的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！