C++：向量下标超出范围？

分类：编程问答

如何解决C++：向量下标超出范围？

我是 C++ 新手，我正在尝试编写一个程序来打开一个文件“parameters.txt”，其中有 8 个空格分隔的数字。然后我在单独的函数 RK4() 中使用这些数字来获得 3 个数组 (y1,y2,t)。然后我在 main() 中操作这些数组并将文件“output.txt”输出到工作目录

这是我的代码：

#include <string>
#include <iostream>
#include <cmath>
#include <fstream>
#include <vector>
#include <algorithm>
#include <iterator>
#include <tuple>
using namespace std;

tuple<vector<double>,vector<double>,vector<double>> RK4() {

    //open parameters.txt,put data into a vector
    ifstream fin("parameters.txt");
    vector<double> data;
    int element;
    while (fin >> element) {
        data.push_back(element);
    }

    //define tspan
    vector<double> tspan(2);
    tspan[0] = 0.0;
    tspan[1] = data[7];

    //define y0
    vector<double> y0(4);
    y0[0] = data[4];
    y0[1] = data[5];
    y0[2] = 0.0;
    y0[3] = 0.0;
    double theta1 = y0[0];
    double theta2 = y0[1];
    double omega1 = y0[2];
    double omega2 = y0[3];

    //define stepSize
    double stepSize;
    stepSize = data[6];

    //define range
    int range = int(tspan[1] / stepSize);

    //define other constants
    double m1,m2,l1,l2;
    m1 = data[0];
    m2 = data[1];
    l1 = data[2];
    l2 = data[3];
    double g = 9.81;

    //define y,t vectors
    vector<double> y1(range);
    vector<double> y2(range);
    vector<double> y3(range);
    vector<double> y4(range);
    vector<double> t(range);
    for (double i = 0.0; i < 1.0 * range; i++) {
        t[i] = i * stepSize;
    }

    //enter y0 into first value
    y1[0] = theta1;
    y2[0] = theta2;
    y3[0] = omega1;
    y4[0] = omega2;

    //loop to find y,t vectors
    for (int i = 0; i < range - 1; i++) {
        //finding all k values:
        //k1
        double dTheta1_1 = y3[i];
        double dOmega1_1 = (-g * (2 * m1 + m2) * sin(y1[i]) - m2 * g * sin(y1[i] - 2 * y2[i]) - 2 * sin(y1[i] - y2[i]) * m2 * (pow(y4[i],2) * l2 + pow(y3[i],2) * l1 * cos(y1[i] - y2[i]))) / (l1 * (2 * m1 + m2 - m2 * cos(2 * y1[i] - 2 * y2[i])));
        double dTheta2_1 = y4[i];
        double dOmega2_1 = (2 * sin(y1[i] - y2[i]) * (pow(y3[i],2) * l1 * (m1 + m2) + g * (m1 + m2) * cos(y1[i]) + pow(y4[i],2) * l2 * m2 * cos(y1[i] - y2[i]))) / (l2 * (2 * m1 + m2 - m2 * cos(2 * y1[i] - 2 * y2[i])));

        //k2
        double dTheta1_2 = y3[i] + 0.5 * stepSize * dTheta1_1;
        double dOmega1_2 = (-g * (2 * m1 + m2) * sin(y1[i] + 0.5 * stepSize * dTheta1_1) - m2 * g * sin((y1[i] + 0.5 * stepSize * dTheta1_1) - 2 * (y2[i] + 0.5 * stepSize * dTheta2_1)) - 2 * sin((y1[i] + 0.5 * stepSize * dTheta1_1) - (y2[i] + 0.5 * stepSize * dTheta2_1)) * m2 * (pow(y4[i] + 0.5 * stepSize * dOmega2_1,2) * l2 + pow(y3[i] + 0.5 * stepSize * dOmega1_1,2) * l1 * cos((y1[i] + 0.5 * stepSize * dTheta1_1) - (y2[i] + 0.5 * stepSize * dTheta2_1)))) / (l1 * (2 * m1 + m2 - m2 * cos(2 * (y1[i] + 0.5 * stepSize * dTheta1_1) - 2 * (y2[i] + 0.5 * stepSize * dTheta2_1))));
        double dTheta2_2 = y4[i] + 0.5 * stepSize * dTheta2_1;
        double dOmega2_2 = (2 * sin((y1[i] + 0.5 * stepSize * dTheta1_1) - (y2[i] + 0.5 * stepSize * dTheta2_1)) * (pow(y3[i] + 0.5 * stepSize * dOmega1_1,2) * l1 * (m1 + m2) + g * (m1 + m2) * cos(y1[i] + 0.5 * stepSize * dTheta1_1) + pow(y4[i] + 0.5 * stepSize * dOmega2_1,2) * l2 * m2 * cos((y1[i] + 0.5 * stepSize * dTheta1_1) - (y2[i] + 0.5 * stepSize * dTheta2_1)))) / (l2 * (2 * m1 + m2 - m2 * cos(2 * (y1[i] + 0.5 * stepSize * dTheta1_1) - 2 * (y2[i] + 0.5 * stepSize * dTheta2_1))));

        //k3
        double dTheta1_3 = y3[i] + 0.5 * stepSize * dTheta1_2;
        double dOmega1_3 = (-g * (2 * m1 + m2) * sin(y1[i] + 0.5 * stepSize * dTheta1_2) - m2 * g * sin((y1[i] + 0.5 * stepSize * dTheta1_2) - 2 * (y2[i] + 0.5 * stepSize * dTheta2_2)) - 2 * sin((y1[i] + 0.5 * stepSize * dTheta1_2) - (y2[i] + 0.5 * stepSize * dTheta2_2)) * m2 * (pow(y4[i] + 0.5 * stepSize * dOmega2_2,2) * l2 + pow(y3[i] + 0.5 * stepSize * dOmega1_2,2) * l1 * cos((y1[i] + 0.5 * stepSize * dTheta1_2) - (y2[i] + 0.5 * stepSize * dTheta2_2)))) / (l1 * (2 * m1 + m2 - m2 * cos(2 * (y1[i] + 0.5 * stepSize * dTheta1_2) - 2 * (y2[i] + 0.5 * stepSize * dTheta2_2))));
        double dTheta2_3 = y4[i] + 0.5 * stepSize * dTheta2_2;
        double dOmega2_3 = (2 * sin((y1[i] + 0.5 * stepSize * dTheta1_2) - (y2[i] + 0.5 * stepSize * dTheta2_2)) * (pow(y3[i] + 0.5 * stepSize * dOmega1_2,2) * l1 * (m1 + m2) + g * (m1 + m2) * cos(y1[i] + 0.5 * stepSize * dTheta1_2) + pow(y4[i] + 0.5 * stepSize * dOmega2_2,2) * l2 * m2 * cos((y1[i] + 0.5 * stepSize * dTheta1_2) - (y2[i] + 0.5 * stepSize * dTheta2_2)))) / (l2 * (2 * m1 + m2 - m2 * cos(2 * (y1[i] + 0.5 * stepSize * dTheta1_2) - 2 * (y2[i] + 0.5 * stepSize * dTheta2_2))));

        //k4
        double dTheta1_4 = y3[i] + stepSize * dTheta1_3;
        double dOmega1_4 = (-g * (2 * m1 + m2) * sin(y1[i] + stepSize * dTheta1_3) - m2 * g * sin((y1[i] + stepSize * dTheta1_3) - 2 * (y2[i] + stepSize * dTheta2_3)) - 2 * sin((y1[i] + stepSize * dTheta1_3) - (y2[i] + stepSize * dTheta2_3)) * m2 * (pow(y4[i] + stepSize * dOmega2_3,2) * l2 + pow(y3[i] + stepSize * dOmega1_3,2) * l1 * cos((y1[i] + stepSize * dTheta1_3) - (y2[i] + stepSize * dTheta2_3)))) / (l1 * (2 * m1 + m2 - m2 * cos(2 * (y1[i] + stepSize * dTheta1_3) - 2 * (y2[i] + stepSize * dTheta2_3))));
        double dTheta2_4 = y4[i] + stepSize * dTheta2_3;
        double dOmega2_4 = (2 * sin((y1[i] + stepSize * dTheta1_3) - (y2[i] + stepSize * dTheta2_3)) * (pow(y3[i] + stepSize * dOmega1_3,2) * l1 * (m1 + m2) + g * (m1 + m2) * cos(y1[i] + stepSize * dTheta1_3) + pow(y4[i] + stepSize * dOmega2_3,2) * l2 * m2 * cos((y1[i] + stepSize * dTheta1_3) - (y2[i] + stepSize * dTheta2_3)))) / (l2 * (2 * m1 + m2 - m2 * cos(2 * (y1[i] + stepSize * dTheta1_3) - 2 * (y2[i] + stepSize * dTheta2_3))));


        double theta1New = y1[i] + (stepSize / 6.0) * (dTheta1_1 + 2 * dTheta1_2 + 2 * dTheta1_3 + dTheta1_4);
        double omega1New = y3[i] + (stepSize / 6.0) * (dOmega1_1 + 2 * dOmega1_2 + 2 * dOmega1_3 + dOmega1_4);
        double theta2New = y2[i] + (stepSize / 6.0) * (dTheta2_1 + 2 * dTheta2_2 + 2 * dTheta2_3 + dTheta2_4);
        double omega2New = y4[i] + (stepSize / 6.0) * (dOmega2_1 + 2 * dOmega2_2 + 2 * dOmega2_3 + dOmega2_4);


        // updating y arrays 
        y1[i + 1] = theta1New;
        y2[i + 1] = theta2New;
        y3[i + 1] = omega1New;
        y4[i + 1] = omega2New;

    }
    return make_tuple(y1,t);
}

int main() {

    //open parameters.txt,put data into a vector
    ifstream fin("parameters.txt");
    vector<double> data;
    int element;
    while (fin >> element) {
        data.push_back(element);
    }
   
    //define tspan
    vector<double> tspan(2);
    tspan[0] = 0.0;
    tspan[1] = 10.0;

    //define stepSize
    double stepSize;
    stepSize = data[6];

    //define range
    int const range = 1000;

    //define other constants
    double l1 = data[2];
    double l2 = data[3];

    //get y1,t from RK4 function
    auto temp = RK4();
    vector<double> y1 = get<0>(temp);
    vector<double> y2 = get<1>(temp);
    vector<double> t = get<2>(temp);
    double x_1[range],y_1[range],x_2[range],y_2[range];

    //define x_1,x_2,y_1,y_2
    for (int i = 0; i < range; i++) {
        x_1[i] = { sin(y1[i]) * l1 };
        y_1[i] = { -cos(y1[i]) * l1 };
        x_2[i] = { sin(y1[i]) * l1 + sin(y2[i]) * l2 };
        y_2[i] = { -cos(y1[i]) * l1 - cos(y2[i]) * l2 };
    }

    //writing x,y positions at time t to output.txt
    ofstream myfile;
    myfile.open("C:\\mydirectory\\output.txt");
    if (myfile.is_open()) {
        myfile << "t: " << endl;
        for (int i = 0; i < range; i++) {
            myfile << t[i] << " ";
        }
        cout << endl;
        myfile << "x_1: " << endl;
        for (int i = 0; i < range; i++) {
            myfile << x_1[i] << " ";
        }
        cout << endl;
        myfile << "y_1: " << endl;
        for (int i = 0; i < range; i++) {
            myfile << y_1[i] << " ";
        }
        cout << endl;
        myfile << "x_2: " << endl;
        for (int i = 0; i < range; i++) {
            myfile << x_2[i] << " ";
        }
        cout << endl;
        myfile << "y_2: " << endl;
        for (int i = 0; i < range; i++) {
            myfile << y_2[i] << " ";
        }
        cout << endl;
        myfile.close();

    }
    else cout << "Unable to open file";

    return 0;
}

当我尝试构建和运行程序（在 Visual Studio 中）时，我收到此错误：

线程 0x22c0 已退出，代码为 0 (0x0)。 调试断言失败！

表达式：向量下标超出范围

有关您的程序如何导致断言的信息 失败，请参阅有关断言的 Visual C++ 文档。

程序已退出，代码为 3 (0x3)。

当我尝试调试程序时，我得到：

抛出异常 c++ 课程 new.exe 触发了断点。

有什么问题？

解决方法

总的来说，这段代码中可能的错误原因有很多，没有明确检查。例如：

您必须检查先决条件。例如：

while (fin >> element) {
        data.push_back(element);
    }

// add some checks
if (data.size() < 8) { ... precondition failed. handle ... }

和

stepSize = data[6];
if (stepSize too small or == 0)  { .. precondition failed. handle ... }

此外，幂函数 pow() 的基数可能不是负数。 这也应该检查。

您还做了很多除法而没有检查除以 0 - 这也可能是导致错误的原因。

,

在这部分

    for (int i = 0; i < range; i++) {
        x_1[i] = { sin(y1[i]) * l1 };
        y_1[i] = { -cos(y1[i]) * l1 };
        x_2[i] = { sin(y1[i]) * l1 + sin(y2[i]) * l2 };
        y_2[i] = { -cos(y1[i]) * l1 - cos(y2[i]) * l2 };
    }

无论实际大小如何，都会从 range 和 y1 读取 1000 (= y2) 个元素。

这可能会导致超出范围的访问。

您应该将 range 设置为它们的元素数量。

由于可变长度数组不在标准 C++ 中，您应该使用 std::vector 代替数组。

线

    int const range = 1000;

应该去掉并行

    double x_1[range],y_1[range],x_2[range],y_2[range];

应该

    int const range = static_cast<int>(y1.size()); 
    std::vector<double> x_1(range),y_1(range),x_2(range),y_2(range);

版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。

相关推荐

matplotlib报错：AttributeError: module 'backend_interagg' has no attribute 'FigureCanvas'. Did you mean: 'FigureCanvasAgg'?
使用本地python环境可以成功执行 import pandas as pd import matplotlib.pyplot as plt # 设置字体 plt.rcParams[&#39;font.sans-serif&#39;] = [&#39;SimHei&#39;] # 能正确显示负号 p
gitlab登录失败，报错：This challenge page was accidentally cached by an intermediary and is no longer available.
设置时间 控制面板
后端开发常见错误
错误1：Request method ‘DELETE‘ not supported 错误还原：controller层有一个接口，访问该接口时报错：Request method ‘DELETE‘ not supported 错误原因：没有接收到前端传入的参数，修改为如下 参考 错误2：cannot r
docker常见错误
错误1：启动docker镜像时报错：Error response from daemon: driver failed programming external connectivity on endpoint quirky_allen 解决方法：重启docker -&gt; systemctl r
idea常见错误
错误1：private field ‘xxx‘ is never assigned 按Altʾnter快捷键，选择第2项 参考：https://blog.csdn.net/shi_hong_fei_hei/article/details/88814070 错误2：启动时报错，不能找到主启动类 #
pip安装依赖失败
报错如下，通过源不能下载，最后警告pip需升级版本 Requirement already satisfied: pip in c:\users\ychen\appdata\local\programs\python\python310\lib\site-packages (22.0.4) Coll
maven常见错误
错误1：maven打包报错 错误还原：使用maven打包项目时报错如下 [ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources (default-resources)
cloud项目中常见错误
错误1：服务调用时报错 服务消费者模块assess通过openFeign调用服务提供者模块hires 如下为服务提供者模块hires的控制层接口 @RestController @RequestMapping(&quot;/hires&quot;) public class FeignControl
springboot常见错误
错误1：运行项目后报如下错误 解决方案 报错2：Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project sb 解决方案：在pom.
springmvc拦截器中使用redisTemplate报空指针异常
参考 错误原因 过滤器或拦截器在生效时，redisTemplate还没有注入 解决方案：在注入容器时就生效 @Component //项目运行时就注入Spring容器 public class RedisBean { @Resource private RedisTemplate&lt;String
vite报错：npm ERR! command C:WINDOWSsystem32cmd.exe /d /s /c C:UsersychenAppDataLocalTempnpx-dde1c848.cmd
使用vite构建项目报错 C:\Users\ychen\work&gt;npm init @vitejs/app @vitejs/create-app is deprecated, use npm init vite instead C:\Users\ychen\AppData\Local\npm-
VM VirtualBox中安装centos时报错：设置基础软件仓库时出错
参考1 参考2 解决方案 # 点击安装源 协议选择 http:// 路径填写 mirrors.aliyun.com/centos/8.3.2011/BaseOS/x86_64/os URL类型 软件库URL 其他路径 # 版本 7 mirrors.aliyun.com/centos/7/os/x86
kafka常见问题
报错1 [root@slave1 data_mocker]# kafka-console-consumer.sh --bootstrap-server slave1:9092 --topic topic_db [2023-12-19 18:31:12,770] WARN [Consumer clie
hive常见问题
错误1 # 重写数据 hive (edu)&gt; insert overwrite table dwd_trade_cart_add_inc &gt; select data.id, &gt; data.user_id, &gt; data.course_id, &gt; date_format(
装载数据时报错：Failed to execute spark task, with exception 'org.apache.hadoop.hive.ql.metadata.HiveException(Failed to create spark client.)'
错误1 hive (edu)&gt; insert into huanhuan values(1,&#39;haoge&#39;); Query ID = root_20240110071417_fe1517ad-3607-41f4-bdcf-d00b98ac443e Total jobs = 1
flume常见问题
报错1：执行到如下就不执行了，没有显示Successfully registered new MBean. [root@slave1 bin]# /usr/local/software/flume-1.9.0/bin/flume-ng agent -n a1 -c /usr/local/softwa
hadoop集群常见错误
虚拟及没有启动任何服务器查看jps会显示jps，如果没有显示任何东西 [root@slave2 ~]# jps 9647 Jps 解决方案 # 进入/tmp查看 [root@slave1 dfs]# cd /tmp [root@slave1 tmp]# ll 总用量 48 drwxr-xr-x. 2
hive常见错误
报错1 hive&gt; show databases; OK Failed with exception java.io.IOException:java.lang.RuntimeException: Error in configuring object Time taken: 0.474 se
Linux常见错误
报错1 [root@localhost ~]# vim -bash: vim: 未找到命令 安装vim yum -y install vim* # 查看是否安装成功 [root@hadoop01 hadoop]# rpm -qa |grep vim vim-X11-7.4.629-8.el7_9.x
使用sqoop一直卡在：mapreduce.Job: Running job: job_1703173956074_0001
修改hadoop配置 vi /usr/local/software/hadoop-2.9.2/etc/hadoop/yarn-site.xml # 添加如下 &lt;configuration&gt; &lt;property&gt; &lt;name&gt;yarn.nodemanager.res
pythonJavaScriptjavaHTMLPHPreactjsC#AndroidCSSNode.jssqlrpython-3.xMysqLjQueryc++pandasFlutterangularIOSdjangolinuxswifttypescript路由器JSON路由器设置无线路由器h3c华三华三路由器设置华三路由器电脑软件教程arraysdocker软件图文教程Cvue.jslaravelspring-boot