Question

我试图将一些整数读入结构中。我让用户输入两个三维向量并返回两个交叉产品和点积。

它似乎正在跳过第二个向量的第二个值。到目前为止，这是我的代码：

/** Write a program to calculate cross-products and dot products of 
**  a 3-dimensional vector:
**  
 **    1. Uses a type definition
**    2. Accepts User input of qty(2) 3-dimensional vectors
**    3. Calculate the cross-product of A x B and B x A                         
**    4. Calculate the dot product A * B
**
******************************************************************/


/************* Preprocessor Functions       **********************/
#include <stdio.h>
#include <stdlib.h>


/************ Structured Data Types ***************************/

typedef struct vector
{
    int x;
    int y;
    int z;
} Vector;


/*************   Declare User Functions  **********************/

int dot_product(Vector a, Vector b);
Vector cross_product(Vector a, Vector b);

/************     Begin MAIN LOOP     *************************/

int main(void)
{
/**      Declare variables     **/
    Vector a, b, c;

    printf("Enter the 3 integer components of the first vector: ");
    scanf("%d%d%d", &(a.x), &(a.y), &(a.z));
    printf("Enter the 3 integer components of the second vector: ");
    scanf("%d%d%d", &(b.x), &(b.y), &(b.y));
    c = cross_product(a, b);
    printf("\n\t(%d %d %d) x (%d %d %d) = (%d %d %d)",   a.x,a.y,a.z,b.x,b.y,b.z,c.x,c.y,c.z);
    c = cross_product(b, a);
    printf("\n\t(%d %d %d) x (%d %d %d) = (%d %d %d)", b.x,b.y,b.z,a.x,a.y,a.z,c.x,c.y,c.z);
    printf("\n\t(%d %d %d) * (%d %d %d) = %d\n", a.x,a.y,a.z,b.x, b.y,b.z,dot_product(a, b));

 /***********   AND CUT!  It's a wrap folks!  Take 5!     ***********/    
    return 0;
}

/**********    User Functions to perform the calculations    ****/

int dot_product(Vector a, Vector b)
{
    return((a.x*b.x)+(a.y*b.y)+(a.z*b.z));
}

Vector cross_product(Vector a, Vector b)
{
Vector c;
c.x = (a.y*b.z)-(a.z*b.y);
c.y = (a.z*b.x)-(a.x*b.z);
c.z = (a.x*b.y)-(a.y*b.x);

return(c);

}

如果用户输入：3 2 1 然后输入：5 6 2

使用的两个载体是：[3 2 1]和[5 2 0]

我在scanf中尝试了％d周围的空格，并且在＆amp; a.x等周围没有括号。

感谢您的关注和任何帮助表示赞赏。仅供全面披露，这是我参加的C编程课程。

Answer 1

你读了b.y两次：

scanf("%d%d%d", &(b.x), &(b.y), &(b.y));

最后一个应该是b.z，否则b.y设置为6，然后被覆盖到2，而b.z永远不会被设置（恰好是0）。

C scanf int into struct

1 个答案: