DA14531中的srand
时间: 2023-09-30 09:06:14 浏览: 40
DA14531是一款低功耗蓝牙芯片,其中的srand函数是用来设置随机数种子的函数。在C语言中,srand函数用于初始化随机数发生器的种子,以便生成伪随机数序列。
使用srand函数可以通过给定一个种子值来初始化随机数发生器。这个种子值可以是任意整数,通常可以使用系统时间作为种子值,以确保每次程序运行都能够生成不同的随机数序列。
下面是srand函数的使用示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include #include <time.h>
int main() {
int i;
// 使用系统时间作为种子值
srand(time(NULL));
// 生成并打印10个随机数
for (i = 0; i < 10; i++) {
printf("%d\n", rand());
}
return 0;
}
```
在上面的示例中,srand函数使用time(NULL)作为种子值,time(NULL)函数返回当前系统时间的秒数。通过这种方式,每次运行程序时都会得到不同的随机数序列。
需要注意的是,在使用rand函数之前需要先调用srand函数进行初始化。否则,每次运行程序都会得到相同的随机数序列。
相关问题
写一个测试rocblas库中的SGEMM的方法
下面是一个简单的使用rocBLAS库中SGEMM函数进行矩阵乘法运算的示例代码:
```c++
#include <iostream>
#include <cstdlib>
#include <ctime>
#include "rocblas.h"
#define N 1024
int main()
{
// 初始化rocBLAS库
rocblas_handle handle;
rocblas_create_handle(&handle);
// 定义矩阵A、B、C
float *A, *B, *C;
A = (float*)malloc(N * N * sizeof(float));
B = (float*)malloc(N * N * sizeof(float));
C = (float*)malloc(N * N * sizeof(float));
// 初始化矩阵A、B、C
srand(time(NULL));
for (int i = 0; i < N; i++) {
for (int j = 0; j < N; j++) {
A[i * N + j] = rand() / (float)RAND_MAX;
B[i * N + j] = rand() / (float)RAND_MAX;
C[i * N + j] = 0.0f;
}
}
// 定义矩阵A、B、C在设备端上的指针
float *dA, *dB, *dC;
rocblas_status status;
status = rocblas_status(rocblas_malloc((void**)&dA, N * N * sizeof(float)));
status = rocblas_status(rocblas_malloc((void**)&dB, N * N * sizeof(float)));
status = rocblas_status(rocblas_malloc((void**)&dC, N * N * sizeof(float)));
// 将矩阵A、B复制到设备端
status = rocblas_set_matrix(N, N, sizeof(float), A, N, dA, N);
status = rocblas_set_matrix(N, N, sizeof(float), B, N, dB, N);
// 设置矩阵A、B、C的参数
float alpha = 1.0f, beta = 0.0f;
rocblas_operation transa = rocblas_operation_none;
rocblas_operation transb = rocblas_operation_none;
rocblas_int lda = N, ldb = N, ldc = N;
// 调用SGEMM函数进行矩阵乘法运算
status = rocblas_sgemm(handle, transa, transb, N, N, N, &alpha, dA, lda, dB, ldb, &beta, dC, ldc);
// 将矩阵C从设备端复制到主机端
status = rocblas_get_matrix(N, N, sizeof(float), dC, N, C, N);
// 输出矩阵C的前10行10列
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
std::cout << C[i * N + j] << " ";
}
std::cout << std::endl;
}
// 释放内存
rocblas_free(dA);
rocblas_free(dB);
rocblas_free(dC);
free(A);
free(B);
free(C);
// 销毁rocBLAS库句柄
rocblas_destroy_handle(handle);
return 0;
}
```
该示例代码中,首先初始化了rocBLAS库,并定义了三个大小为1024×1024的矩阵A、B、C,并对矩阵A、B进行了随机初始化。然后,分配了矩阵A、B、C在设备端上的内存,并将矩阵A、B从主机端复制到设备端。接下来,调用rocBLAS库中的SGEMM函数进行矩阵乘法运算,并将结果从设备端复制到主机端。最后,输出了矩阵C的前10行10列,并释放了内存。
在linux系统中使用qt creator实现2048源代码
首先需要安装Qt Creator和Qt库。安装完成后,可以按照以下步骤进行实现:
1. 新建Qt Widgets Application项目。
2. 在项目中添加四个Label和一个PushButton,用于显示游戏界面和重新开始游戏。
3. 编写游戏逻辑代码,实现游戏的初始化、移动、合并等操作。
4. 将游戏逻辑代码与界面进行连接,实现游戏的展示和操作。
5. 编写结束判断代码,当游戏结束时弹出游戏结束提示框。
6. 部署程序,生成可执行文件。
下面是一个简单的2048实现示例代码:
mainwindow.h文件:
```cpp
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QLabel>
#include <QPushButton>
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
private:
QLabel *box[4][4];
QPushButton *restartBtn;
int score;
bool gameover;
void initGame();
void clearBox();
void newBox();
void updateBox();
void moveLeft();
void moveRight();
void moveUp();
void moveDown();
bool canMove();
bool canCombine();
bool isGameOver();
void gameOver();
int getRand(int min, int max);
private slots:
void restartGame();
void keyPressEvent(QKeyEvent *event);
};
#endif // MAINWINDOW_H
```
mainwindow.cpp文件:
```cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QKeyEvent>
#include <QMessageBox>
#include <ctime>
#include <cstdlib>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
// 设置窗口大小
setFixedSize(400, 400);
// 新建重新开始按钮
restartBtn = new QPushButton(this);
restartBtn->setText("重新开始");
restartBtn->setGeometry(290, 30, 100, 30);
connect(restartBtn, SIGNAL(clicked(bool)), this, SLOT(restartGame()));
// 新建游戏盒子
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
box[i][j] = new QLabel(this);
box[i][j]->setGeometry(20 + i * 90, 100 + j * 90, 80, 80);
box[i][j]->setStyleSheet("background-color: #bbada0; border-radius: 5px; font-size: 36px; font-weight: bold; color: #776e65; text-align: center;");
box[i][j]->setText("");
}
}
// 初始化游戏
initGame();
}
MainWindow::~MainWindow()
{
}
void MainWindow::initGame()
{
// 清空游戏盒子
clearBox();
// 初始化得分和游戏状态
score = 0;
gameover = false;
// 新建两个数字盒子
newBox();
newBox();
// 更新游戏盒子
updateBox();
}
void MainWindow::clearBox()
{
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
box[i][j]->setText("");
}
}
}
void MainWindow::newBox()
{
int i, j;
do {
i = getRand(0, 3);
j = getRand(0, 3);
} while (box[i][j]->text() != "");
int value = getRand(1, 2) * 2;
box[i][j]->setText(QString::number(value));
}
void MainWindow::updateBox()
{
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
int value = box[i][j]->text().toInt();
if (value == 0) {
box[i][j]->setText("");
} else {
box[i][j]->setText(QString::number(value));
}
switch (value) {
case 0:
box[i][j]->setStyleSheet("background-color: #bbada0; border-radius: 5px; font-size: 36px; font-weight: bold; color: #776e65; text-align: center;");
break;
case 2:
box[i][j]->setStyleSheet("background-color: #eee4da; border-radius: 5px; font-size: 36px; font-weight: bold; color: #776e65; text-align: center;");
break;
case 4:
box[i][j]->setStyleSheet("background-color: #ede0c8; border-radius: 5px; font-size: 36px; font-weight: bold; color: #776e65; text-align: center;");
break;
case 8:
box[i][j]->setStyleSheet("background-color: #f2b179; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 16:
box[i][j]->setStyleSheet("background-color: #f59563; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 32:
box[i][j]->setStyleSheet("background-color: #f67c5f; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 64:
box[i][j]->setStyleSheet("background-color: #f65e3b; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 128:
box[i][j]->setStyleSheet("background-color: #edcf72; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 256:
box[i][j]->setStyleSheet("background-color: #edcc61; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 512:
box[i][j]->setStyleSheet("background-color: #edc850; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 1024:
box[i][j]->setStyleSheet("background-color: #edc53f; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
case 2048:
box[i][j]->setStyleSheet("background-color: #edc22e; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
default:
box[i][j]->setStyleSheet("background-color: #3c3a32; border-radius: 5px; font-size: 36px; font-weight: bold; color: #f9f6f2; text-align: center;");
break;
}
}
}
}
void MainWindow::moveLeft()
{
bool flag = false;
for (int i = 0; i < 4; i++) {
int last = -1;
for (int j = 0; j < 4; j++) {
if (box[i][j]->text() == "") {
continue;
}
if (last == -1) {
last = j;
} else {
if (box[i][last]->text() == box[i][j]->text()) {
int value = box[i][j]->text().toInt() * 2;
score += value;
box[i][last]->setText(QString::number(value));
box[i][j]->setText("");
last = -1;
flag = true;
} else {
last = j;
}
}
}
if (last != -1) {
if (last != i) {
box[i][last]->setText(box[i][i]->text());
box[i][i]->setText("");
flag = true;
}
}
}
if (flag) {
newBox();
updateBox();
}
}
void MainWindow::moveRight()
{
bool flag = false;
for (int i = 0; i < 4; i++) {
int last = -1;
for (int j = 3; j >= 0; j--) {
if (box[i][j]->text() == "") {
continue;
}
if (last == -1) {
last = j;
} else {
if (box[i][last]->text() == box[i][j]->text()) {
int value = box[i][j]->text().toInt() * 2;
score += value;
box[i][last]->setText(QString::number(value));
box[i][j]->setText("");
last = -1;
flag = true;
} else {
last = j;
}
}
}
if (last != -1) {
if (last != i) {
box[i][last]->setText(box[i][i]->text());
box[i][i]->setText("");
flag = true;
}
}
}
if (flag) {
newBox();
updateBox();
}
}
void MainWindow::moveUp()
{
bool flag = false;
for (int j = 0; j < 4; j++) {
int last = -1;
for (int i = 0; i < 4; i++) {
if (box[i][j]->text() == "") {
continue;
}
if (last == -1) {
last = i;
} else {
if (box[last][j]->text() == box[i][j]->text()) {
int value = box[i][j]->text().toInt() * 2;
score += value;
box[last][j]->setText(QString::number(value));
box[i][j]->setText("");
last = -1;
flag = true;
} else {
last = i;
}
}
}
if (last != -1) {
if (last != j) {
box[last][j]->setText(box[j][j]->text());
box[j][j]->setText("");
flag = true;
}
}
}
if (flag) {
newBox();
updateBox();
}
}
void MainWindow::moveDown()
{
bool flag = false;
for (int j = 0; j < 4; j++) {
int last = -1;
for (int i = 3; i >= 0; i--) {
if (box[i][j]->text() == "") {
continue;
}
if (last == -1) {
last = i;
} else {
if (box[last][j]->text() == box[i][j]->text()) {
int value = box[i][j]->text().toInt() * 2;
score += value;
box[last][j]->setText(QString::number(value));
box[i][j]->setText("");
last = -1;
flag = true;
} else {
last = i;
}
}
}
if (last != -1) {
if (last != j) {
box[last][j]->setText(box[j][j]->text());
box[j][j]->setText("");
flag = true;
}
}
}
if (flag) {
newBox();
updateBox();
}
}
bool MainWindow::canMove()
{
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
if (box[i][j]->text() == "") {
return true;
}
if (i > 0 && box[i][j]->text() == box[i - 1][j]->text()) {
return true;
}
if (i < 3 && box[i][j]->text() == box[i + 1][j]->text()) {
return true;
}
if (j > 0 && box[i][j]->text() == box[i][j - 1]->text()) {
return true;
}
if (j < 3 && box[i][j]->text() == box[i][j + 1]->text()) {
return true;
}
}
}
return false;
}
bool MainWindow::canCombine()
{
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
if (i > 0 && box[i][j]->text() == box[i - 1][j]->text()) {
return true;
}
if (i < 3 && box[i][j]->text() == box[i + 1][j]->text()) {
return true;
}
if (j > 0 && box[i][j]->text() == box[i][j - 1]->text()) {
return true;
}
if (j < 3 && box[i][j]->text() == box[i][j + 1]->text()) {
return true;
}
}
}
return false;
}
bool MainWindow::isGameOver()
{
if (canMove()) {
return false;
}
if (canCombine()) {
return false;
}
return true;
}
void MainWindow::gameOver()
{
gameover = true;
QMessageBox::information(this, "游戏结束", "得分:" + QString::number(score));
}
int MainWindow::getRand(int min, int max)
{
srand(time(NULL));
return rand() % (max - min + 1) + min;
}
void MainWindow::restartGame()
{
initGame();
}
void MainWindow::keyPressEvent(QKeyEvent *event)
{
if (gameover) {
return;
}
switch (event->key()) {
case Qt::Key_Left:
moveLeft();
if (isGameOver()) {
gameOver();
}
break;
case Qt::Key_Right:
moveRight();
if (isGameOver()) {
gameOver();
}
break;
case Qt::Key_Up:
moveUp();
if (isGameOver()) {
gameOver();
}
break;
case Qt::Key_Down:
moveDown();
if (isGameOver()) {
gameOver();
}
break;
default:
break;
}
}
```
编译运行后,即可在窗口中玩2048游戏。