为什么我的 Struct 没有通过 C 中的点符号检索正确的信息？

Question

我正在尝试编写一个程序，它从用户那里获取 2 个圆的 X-Y 坐标和半径。然后，它会判断2个圆是否相交或包含在另一个圆中。

对于 contain() 函数，当我尝试打印出 c1.x 和 c2.x 的值时，只有 c1.x 似乎给我用户输入，而 c2.x 打印出一个对我没有意义的非常大的数字。为什么我无法检索 c2.x 的用户输入？谢谢

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

struct circle {
    double radius;
    double x;
    double y;
};
// Returns 1 if the Circle intersects
int intersect(struct circle c1, struct circle c2);
int contain(struct circle *c1, struct circle *c2);

int main(){
    struct circle c1, c2;
    int answer, selection;
    do{
        printf("Please choose a Function to be used!!!\n");
        printf("1: Enter the Parameters of the 2 Circles:\n");
        printf("2: intersect():\n");
        printf("3: contain():\n");
        printf("4: Quit!!\n");
        scanf("%d", &selection);
        switch(selection){
            case 1:{
                // First Circle
                printf("Please Enter the Radius, X-Coordinate and Y-Coordinate of the First Circle\n");
                printf("Radius:\n");
                scanf("%d", &c1.radius);
                printf("X-Coordinate:\n");
                scanf("%d", &c1.x);
                printf("Y-Coordinate:\n");
                scanf("%d", &c1.y);
                // Second Circle
                printf("Please Enter the Radius, X-Coordinate and Y-Coordinate of the Second Circle\n");
                printf("Radius:\n");
                scanf("%d", &c2.radius);
                printf("X-Coordinate:\n");
                scanf("%d", &c2.x);
                printf("Y-Coordinate:\n");
                scanf("%d", &c2.y);
                break;
            }
            case 2:{
                int choice = intersect(c1, c2);
                switch(choice){
                    case 1:{
                        printf("The 2 Circles intersects!\n");
                        break;
                    }
                    case 2:{
                        printf("The 2 Circles does not intersects!!\n");
                    }
                }
                break;
            }
            case 3:{
                answer = contain(&c1,&c2);
                if(answer == 1){
                    printf("Circle C1 contains Circle C2!!\n");
                }
                else{
                    printf("Circle C1 does not contain Circle C2!!\n");
                }
            }
        }
    } while (selection < 4);

    return 0;
}


int intersect(struct circle c1, struct circle c2){
    // Calculate the Distance between the Centers of 2 Circles
    double xDiff, yDiff, dist, dRadii;
    xDiff = pow(c1.x,2) - pow(c2.x,2);
    printf("X Coordinate of C1 and C2: %d, %d\n", c1.x,c2.x);
    printf("%d", xDiff);
    if(xDiff < 0){
        xDiff = -xDiff;
    }
    yDiff = pow(c1.y,2) - pow(c2.y,2);
    if(yDiff < 0){
        yDiff = -yDiff;
    }
    dist = sqrt(xDiff + yDiff);
    dRadii = c1.radius + c2.radius;
    if((dist == dRadii) || (dist < dRadii)){
        return 1;
    }
    else{
        return 0;
    }
}

int contain(struct circle *c1, struct circle *c2){
    double specialValue;
    double xDiff, yDiff, dist, dRadii;
    xDiff = pow(c1->x,2) - pow(c2->x,2);
    if(xDiff < 0){
        xDiff = -xDiff;
    }
    yDiff = pow(c1->y,2) - pow(c2->y,2);
    if(yDiff < 0){
        yDiff = -yDiff;
    }
    dist = sqrt(xDiff + yDiff);
    specialValue = dist + c2->radius;
    // Checking
    if((c1->radius > specialValue) || (c1->radius == specialValue)){
        return 1;
    }
    else{
        return 0;
    }

}

Answer 1

intersect 函数的参数传递存在一些问题，printf.

的格式说明符存在一些其他问题

尝试这样的事情：

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

struct circle {
    double radius;
    double x;
    double y;
};
// Returns 1 if the Circle intersects
int intersect(struct circle *c1, struct circle *c2);
int contain(struct circle *c1, struct circle *c2);

int main(){
    struct circle c1, c2;
    int answer, selection;
    do{
        printf("Please choose a Function to be used!!!\n");
        printf("1: Enter the Parameters of the 2 Circles:\n");
        printf("2: intersect():\n");
        printf("3: contain():\n");
        printf("4: Quit!!\n");
        scanf("%d", &selection);
        switch(selection){
            case 1:{
                // First Circle
                printf("Please Enter the Radius, X-Coordinate and Y-Coordinate of the First Circle\n");
                printf("Radius:\n");
                scanf("%lf", &c1.radius);
                printf("X-Coordinate:\n");
                scanf("%lf", &c1.x);
                printf("Y-Coordinate:\n");
                scanf("%lf", &c1.y);
                // Second Circle
                printf("Please Enter the Radius, X-Coordinate and Y-Coordinate of the Second Circle\n");
                printf("Radius:\n");
                scanf("%lf", &c2.radius);
                printf("X-Coordinate:\n");
                scanf("%lf", &c2.x);
                printf("Y-Coordinate:\n");
                scanf("%lf", &c2.y);
                break;
            }
            case 2:{
                int choice = intersect(&c1, &c2);
                switch(choice){
                    case 1:{
                        printf("The 2 Circles intersects!\n");
                        break;
                    }
                    case 2:{
                        printf("The 2 Circles does not intersects!!\n");
                    }
                }
                break;
            }
            case 3:{
                answer = contain(&c1,&c2);
                if(answer == 1){
                    printf("Circle C1 contains Circle C2!!\n");
                }
                else{
                    printf("Circle C1 does not contain Circle C2!!\n");
                }
            }
        }
    } while (selection < 4);

    return 0;
}


int intersect(struct circle *c1, struct circle *c2){
    // Calculate the Distance between the Centers of 2 Circles
    double xDiff, yDiff, dist, dRadii;
    xDiff = pow(c1->x,2) - pow(c2->x,2);
    printf("X Coordinate of C1 and C2: %lf, %lf\n", c1->x,c2->x);
    printf("%lf\n", xDiff);
    if(xDiff < 0){
        xDiff = -xDiff;
    }
    yDiff = pow(c1->y,2) - pow(c2->y,2);
    if(yDiff < 0){
        yDiff = -yDiff;
    }
    dist = sqrt(xDiff + yDiff);
    dRadii = c1->radius + c2->radius;
    if((dist == dRadii) || (dist < dRadii)){
        return 1;
    }
    else{
        return 0;
    }
}

int contain(struct circle *c1, struct circle *c2){
    double specialValue;
    double xDiff, yDiff, dist, dRadii;
    xDiff = pow(c1->x,2) - pow(c2->x,2);
    if(xDiff < 0){
        xDiff = -xDiff;
    }
    yDiff = pow(c1->y,2) - pow(c2->y,2);
    if(yDiff < 0){
        yDiff = -yDiff;
    }
    dist = sqrt(xDiff + yDiff);
    specialValue = dist + c2->radius;
    // Checking
    if((c1->radius > specialValue) || (c1->radius == specialValue)){
        return 1;
    }
    else{
        return 0;
    }

}

如有其他问题，请添加演示用户输入和预期输出。

Answer 2

struct circle {
    double radius;
    double x;
    double y;
};

这里，结构成员是double数据类型。所以你必须使用 %lf 而不是 %d 这是整数的格式说明符。

在 main() 中执行此操作：

                scanf("%lf", &c1.radius);
                printf("X-Coordinate:\n");
                scanf("%lf", &c1.x);
                printf("Y-Coordinate:\n");
                scanf("%lf", &c1.y);
                // Second Circle
                printf("Please Enter the Radius, X-Coordinate and Y-Coordinate of the Second Circle\n");
                printf("Radius:\n");
                scanf("%lf", &c2.radius);
                printf("X-Coordinate:\n");
                scanf("%lf", &c2.x);
                printf("Y-Coordinate:\n");
                scanf("%lf", &c2.y);

在相交（）中：

 printf("%lf", xDiff);

为什么我的 Struct 没有通过 C 中的点符号检索正确的信息？

Why isn't my Struct retrieving the right information via dot notation in C?

c

struct