这段代码有什么问题？编译多项式曲线下的面积（ax2 + bx + c） [英] What is wrong with this code? Compiling area under curve of a polynomial (ax2 +bx +c)

问题描述

#include <stdio.h>
#include <math.h>
int compute_polynomial (int a, int b, int c, int x){             //prototype
	int fx;
       fx = a* pow(x,2) + b*x + c ;	
       return (fx);
}
double trapezoid_area (int x1, int x2, int fx1, int fx2){        //prototype
	double area;
	area = (fx1 + fx2)* (x2-x1) / 2;
	return (area);
}
double auc_polinomial (int a, int b, int c, int partitions, int x_low, int x_high) {        //prototype
	double total_area = 0;
	int x1, x2, one_partition;
	int fx1, fx2;
	double trap_area;
	one_partition = (x_high - x_low)/ partitions;
	for (x1 = x_low; x1<=x_high; x1 += one_partition){
		fx1= compute_polynomial (a, b, c, x1);
		for (x2= x_low + one_partition; x2<=x_high; x2 += one_partition){ 
	    fx2= compute_polynomial (a, b ,c, x2);
		}
		trap_area = trapezoid_area (x1,x2, fx1, fx2);
		total_area += trap_area; 
       
	}
	return (total_area);
}

int main (){
   int a,b,c;
   int x_low, x_high;
   int partitions;
   double total_area;
   

   printf("Enter three polinomial coefficents in order a b c : ");
   scanf("%d %d %d", &a, &b, &c);
   printf("Enter x interval: ");
   scanf("%d %d", &x_low, &x_high);
   printf("Enter number of partitions: ");
   scanf("%d", &partitions);
   total_area = auc_polinomial( a, b, c, partitions, x_low, x_high);
   printf(" AUC: %f", total_area);
   return (0); 
   

}

我的尝试：



我已经执行了它，但AUC结果没有显示在屏幕上。我只知道编译总区域时for循环有问题。

What I have tried:

I already executed it, but the AUC result doesnt appear on the screen. I just know that there is something wrong with the "for" loop when I compile the total area.

推荐答案

引用：

我只知道编译总区域时for循环有问题。

I just know that there is something wrong with the "for" loop when I compile the total area.

然后使用调试器看看是什么你的代码真的在做。



有一个工具可以让你看到你的代码在做什么，它的名字是调试器。它也是一个很好的学习工具，因为它向你展示了现实，你可以看到哪种期望与现实相符。

当你不明白你的代码在做什么或为什么它做它做的时候，答案就是答案是调试器。

使用调试器查看代码正在执行的操作。只需设置断点并查看代码执行情况，调试器允许您逐行执行第1行并在执行时检查变量。



调试器 - 维基百科，免费的百科全书 [ ^ ]



掌握Visual Studio 2010中的调试 - 初学者指南 [ ^ ]

使用Visual Studio 2010进行基本调试 - YouTube [ ^ ]

调试器在这里向您展示您的代码正在做什么，您的任务是与什么进行比较应该这样做。

调试器中没有魔法，它没有找到错误，它只是帮助你。当代码没有达到预期的效果时，你就接近了一个bug。

Then use the debugger to see what your code is really doing.

There is a tool that allow you to see what your code is doing, its name is debugger. It is also a great learning tool because it show you reality and you can see which expectation match reality.
When you don't understand what your code is doing or why it does what it does, the answer is debugger.
Use the debugger to see what your code is doing. Just set a breakpoint and see your code performing, the debugger allow you to execute lines 1 by 1 and to inspect variables as it execute.

Debugger - Wikipedia, the free encyclopedia[^]

Mastering Debugging in Visual Studio 2010 - A Beginner's Guide[^]
Basic Debugging with Visual Studio 2010 - YouTube[^]
The debugger is here to show you what your code is doing and your task is to compare with what it should do.
There is no magic in the debugger, it don't find bugs, it just help you to. When the code don't do what is expected, you are close to a bug.

你应该修改你的数据类型选择。对于这种计算，你应该为每个变量使用 double 数据类型。

You should revise your data type choices. For such kind of computation you should use double datatype for every variable.

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