加载"lab1data.txt".里面是50个节点的位置信息，用matlab写一个gossiping协议，每个节点随机向邻居两个节点发送数据包计算到达所有节点的跳数和数据包个数

首先，读入数据并初始化节点：

data = load('lab1data.txt');
num_nodes = size(data, 1);
nodes = cell(num_nodes, 1);
for i = 1:num_nodes
    nodes{i}.id = i;
    nodes{i}.neighbors = findNeighbors(data(i,:), data);
    nodes{i}.msgs_received = zeros(num_nodes, 1);
    nodes{i}.num_msgs_sent = 0;
    nodes{i}.visited = false;
end

其中，`findNeighbors`函数用于找到一个节点的所有邻居：

function neighbors = findNeighbors(pos, data)
    num_nodes = size(data, 1);
    neighbors = [];
    for i = 1:num_nodes
        if i ~= pos(1) && norm(data(i,:) - pos) <= 1.5
            neighbors(end+1) = i;
        end
    end
end

接下来，实现gossiping协议。每个节点随机向两个邻居发送一个数据包，并在收到数据包后继续向两个随机邻居发送数据包，直到所有节点都被访问过：

num_msgs_sent = 0;
hop_count = 0;
while ~all(cellfun(@(node) node.visited, nodes))
    for i = 1:num_nodes
        if ~nodes{i}.visited
            neighbors = nodes{i}.neighbors;
            if length(neighbors) >= 2
                indices = randsample(length(neighbors), 2);
                for j = indices
                    nodes{neighbors(j)}.msgs_received(i) = 1;
                    nodes{i}.num_msgs_sent = nodes{i}.num_msgs_sent + 1;
                    num_msgs_sent = num_msgs_sent + 1;
                end
            end
        end
    end
    hop_count = hop_count + 1;
    for i = 1:num_nodes
        if ~nodes{i}.visited && sum(nodes{i}.msgs_received) > 0
            nodes{i}.visited = true;
            indices = randsample(length(nodes{i}.neighbors), 2);
            for j = indices
                nodes{nodes{i}.neighbors(j)}.msgs_received(i) = 1;
                nodes{i}.num_msgs_sent = nodes{i}.num_msgs_sent + 1;
                num_msgs_sent = num_msgs_sent + 1;
            end
        end
    end
end

最后输出跳数和数据包个数：

disp(['Total hop count: ' num2str(hop_count)]);
disp(['Total number of messages sent: ' num2str(num_msgs_sent)]);

完整代码如下：

data = load('lab1data.txt');
num_nodes = size(data, 1);
nodes = cell(num_nodes, 1);
for i = 1:num_nodes
    nodes{i}.id = i;
    nodes{i}.neighbors = findNeighbors(data(i,:), data);
    nodes{i}.msgs_received = zeros(num_nodes, 1);
    nodes{i}.num_msgs_sent = 0;
    nodes{i}.visited = false;
end

num_msgs_sent = 0;
hop_count = 0;
while ~all(cellfun(@(node) node.visited, nodes))
    for i = 1:num_nodes
        if ~nodes{i}.visited
            neighbors = nodes{i}.neighbors;
            if length(neighbors) >= 2
                indices = randsample(length(neighbors), 2);
                for j = indices
                    nodes{neighbors(j)}.msgs_received(i) = 1;
                    nodes{i}.num_msgs_sent = nodes{i}.num_msgs_sent + 1;
                    num_msgs_sent = num_msgs_sent + 1;
                end
            end
        end
    end
    hop_count = hop_count + 1;
    for i = 1:num_nodes
        if ~nodes{i}.visited && sum(nodes{i}.msgs_received) > 0
            nodes{i}.visited = true;
            indices = randsample(length(nodes{i}.neighbors), 2);
            for j = indices
                nodes{nodes{i}.neighbors(j)}.msgs_received(i) = 1;
                nodes{i}.num_msgs_sent = nodes{i}.num_msgs_sent + 1;
                num_msgs_sent = num_msgs_sent + 1;
            end
        end
    end
end

disp(['Total hop count: ' num2str(hop_count)]);
disp(['Total number of messages sent: ' num2str(num_msgs_sent)]);

function neighbors = findNeighbors(pos, data)
    num_nodes = size(data, 1);
    neighbors = [];
    for i = 1:num_nodes
        if i ~= pos(1) && norm(data(i,:) - pos) <= 1.5
            neighbors(end+1) = i;
        end
    end
end