qsrand(time(NULL));

This is C++ code that initializes the random number generator with a seed value based on the current time.

The function `time(NULL)` returns the current time in seconds since January 1, 1970 (also known as the Unix epoch). This value is used as the seed for the random number generator.

The `qsrand()` function is a part of the Qt library, and it sets the seed value for the random number generator used by Qt. This function is commonly used in games and simulations to generate random numbers for various purposes, such as generating random positions for game objects, randomizing AI behavior, or determining the outcome of events.

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time(NULL)

time(NULL)函数用于获取当前系统时间，返回的结果是一个time_t类型，表示从UTC时间1970年1月1日00:00:00（也称为UNIX系统的Epoch时间）到当前时刻的秒数。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
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time（NULL）

`time(NULL)` 是一个 C 标准库函数，用于获取当前系统时间（以秒为单位），返回值类型为 `time_t`。它需要传入一个参数，指向一个 `time_t` 类型的变量，若该参数为 NULL，则返回当前时间。例如，下面的代码可以获取当前时间并打印出来：

#include <stdio.h>
#include <time.h>

int main() {
    time_t current_time;
    current_time = time(NULL);
    printf("当前时间为：%s", ctime(&current_time));
    return 0;
}

其中，`ctime` 函数将 `time_t` 类型的时间转换为一个字符串表示。