Mathematics functions allow you to perform. mathematical operations. Expand the category to view a list of the available functions.
Function Name | Description |
floor | Gets the largest integral value that is less than x. |
rand | Gets a random integer between 0 and RAND_MAX. |
sqrt | Computes the square root of x. |
srand | Seeds the pseudo-random number generator. |
例子：
double sqrt(double x); //开平方根需要事先声明
lr_output_message ("Square root of 9 = %f\n", sqrt(9));
lr_output_message ("Square root of 8 = %f\n", sqrt(8));
lr_output_message ("Square root of -8 = %f\n", sqrt(-8));
例子：
//调用rand之前先调用srand
srand(time(NULL));
//返回数值范围是0-RAND_MAX伪随机整数
lr_output_message ("A number between (0,100): %d\n", rand() % 100);
lr_output_message ("A number between (20,30): %d\n", rand() % 10+20);
//调用rand之前先调用srand
//返回数值范围是0-RAND_MAX伪随机整数
srand(time(NULL));
//返回数值范围是0-RAND_MAX伪随机整数0到100
lr_output_message
("A number between (0,100): %d\n", rand() % 100);
例子：
double floor(double x); //显示声明
//整数部分取整，小数部分为零
lr_output_message ("floor of 2.3 is %.1lf\n", floor(2.3));
lr_output_message ("floor of 3.8 is %.1lf\n", floor(3.8));
//负数往小取负整数
lr_output_message ("floor of -2.3 is %.1lf\n", floor(-2.3));
lr_output_message ("floor of -3.8 is %.1lf\n", floor(-3.8));
