浮动随机化后程序崩溃

Question

在计算圆[3] [6]时,程序似乎在第54行崩溃.可能是什么导致了这个？我输入了一堆打印语句来查找一些信息,所有内容似乎都很好,直到完全[3] [6],这似乎没什么特别的,它崩溃.

int main() {

double a, b, circleXMax, circleYMax, circleRMax;
double rand_float(double a, double b);
int i, j;
int circleInfo = 3;
int circleNum = 50;
int PI = 3.14;
double circleArea;
double circleAreaMax = 0;
double circles[circleInfo][circleNum];

printf("Opened \n");

for(i = 1; i <= circleNum; i++) {
    printf("Start of i = %d \n", i);
    for(j = 1; j <= circleInfo; j++) {
        printf("Start of j = %d \n", j);
        if(j == 1 || j == 2) {
            printf("Start of randomization of j (%d) \n", j);
            circles[j][i] = rand_float(100.00, 900.00);
            printf("circles[%d][%d] = %f \n", j, i, circles[j][i]);
        }
        else {
            printf("Start of randomization of j (%d) \n", j);
            circles[j][i] = rand_float(0.00, 100.00);
            printf("circles[%d][%d] = %f \n", j, i, circles[j][i]);
        }
    }
    printf("Start of calculation of circleArea \n");
    circleArea = PI * circles[3][i] * circles[3][i];
    printf("Completed calculation of circleArea = %f \n", circleArea);
    if(circleArea >= circleAreaMax) {
        printf("circle was larger then maximum current \n");
        circleAreaMax = circleArea;
        circleXMax = circles[1][i];
        circleYMax = circles[2][i];
        circleRMax = circles[3][i];
    } else {
        printf("circle was NOT larger then maximum current \n");
    }
}

printf("Circle with largest area (%f) has\n", circleAreaMax);
printf("center (%f, %f) and radius %f", circleXMax, circleYMax, circleRMax);

   }

   double rand_float(double a, double b) {
      printf("doing a randomization via rand_float \n");
      return (((double)rand()/RAND_MAX)*(b-a))+a;
   }

说完后崩溃了:

"j = 3的开头"

"j(3)的随机化开始"

"通过rand_float进行随机化"

Answer 1

我注意到的问题是循环边界.两种情况

 for(i = 1; i <= circleNum; i++)

和

for(j = 1; j <= circleInfo; j++)

导致一个错误.

C数组具有基于0的索引,因此对于定义的数组<type> arr[m][n],最高可能的有效索引将是arr[m-1][n-1].

那说,其他一些评论:

• 你有里面的函数声明main(),它们需要在文件范围内才能对整个翻译单元可见.否则,只有main()在它们之后定义的函数才能获得它们的声明.
• int main()应该是int main(void),托管环境符合标准(除非您使用明确定义前者的专用环境是有效签名).