From f23b01ef35628f9519b5b64977650baa635a1997 Mon Sep 17 00:00:00 2001
From: pyvawtjzl <robocoder@foxmail.com>
Date: Wed, 12 Mar 2025 09:55:38 +0800
Subject: [PATCH] ADD file via upload

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+[TOC]
+
+---
+
+## MPI中的集合通信与广播
+
+### 任务描述
+
+本关任务：使用MPI中的`MPI_Reduce`和`MPI_Bcast`函数实现用户自定义输入的梯形法则近似计算积分面积。
+
+### 相关知识
+
+为了完成本关任务，你需要掌握：1.MPI中的梯形法则，2.如何使用`MPI_Bcast`集合通信函数将单个进程的数据发送到通信域中所有进程，3如何使用`MPI_Reduce`集合通信函数将通信域中所有进程的数据汇总。
+
+#### 梯形法则
+
+<img width="100%" src="/api/attachments/WUpBQ3hFN3ZwY1FLcE1RWWdhU010dz09?type=image/png)" alt="" />
+
+梯形法则是指为了计算图（a）中从`a`到`b`阴影部分的面积，将该区域划分为`n`个子区域，每个子区域用梯形面积计算公式计算，最终将`n`个小梯形汇总求和作为所求面积大小的近似结果。
+
+#### MPI_Bcast
+
+`MPI_Bcast` - Broadcasts a message from the process with rank root to all other processes of the group.
+
+```c
+int MPI_Bcast(void *buffer, int count, MPI_Datatype datatype,
+    int root, MPI_Comm comm)
+```
+
+INPUT/OUTPUT PARAMETERS
+
+- `buffer`: Starting address of buffer (choice).
+- `count`: Number of entries in buffer (integer).
+- `datatype`: Data type of buffer (handle).
+- `root`: Rank of broadcast root (integer).
+- `comm`: Communicator (handle).
+- `info`: Info (handle, persistent only).
+
+OUTPUT PARAMETERS
+
+- `request`: Request (handle, non-blocking and persistent only).
+- `ierror`: Fortran only: Error status (integer).
+
+#### MPI_Reduce
+
+`MPI_Reduce` - Reduces values on all processes within a group.
+
+```c
+int MPI_Reduce(const void *sendbuf, void *recvbuf, int count,
+               MPI_Datatype datatype, MPI_Op op, int root,
+               MPI_Comm comm)
+```
+
+INPUT PARAMETERS
+
+- `sendbuf`: Address of send buffer (choice).
+- `count`: Number of elements in send buffer (integer).
+- `datatype`: Data type of elements of send buffer (handle).
+- `op`: Reduce operation (handle).
+- `root`: Rank of root process (integer).
+- `comm`: Communicator (handle).
+- `info`: Info (handle, persistent only).
+
+OUTPUT PARAMETERS
+
+- `recvbuf`: Address of receive buffer (choice, significant only at root).
+- `request`: Request (handle, non-blocking and persistent only).
+- `ierror`: Fortran only: Error status (integer).
+
+### 编程要求
+
+根据提示，在右侧编辑器补充两处注释部分代码，计算并输出阴影面积的大小。
+
+### 测试说明
+
+平台会对你编写的代码进行测试：
+
+测试输入：`0 3 1024`；
+预期输出：
+`9.000`
+
+测试输入：`1 7 2048`；
+预期输出：
+`114.000`
+
+---
+
+开始你的任务吧，祝你成功！