how can fix this error of this code?

names = {'1' '2' '3' '4' '5' '6' '7' '8' 'A' 'B' 'C'};
A1=[1 0 0 0 5 0 0 5 0 0 0; ...
   0 1 0  0 0 0 5 5 0 0 0; ...
   0 0 1 10 5 0 0 0 0 0 0;...
   0 0 10 1 0 0 3 0 0 0 0;...
   5 0 5  0 1 0 0 0 1 0 0; ...
   0 0 0  0 0 1 0 5 0 1 0;...
   0 5 0  3 0 0 1 0 0 0 1;...
   5 5 0  0 0 5 0 1 0 0 0;...
   0 0 0  0 1 0 0 0 1 0 0;...
   0 0 0  0 0 1 0 0 0 1 0;...
   0 0 0  0 0 0 1 0 0 0 1];

    
    % Initialize variables
    start_node = names == 'A';    % index of starting node
    end_nodes = names == 'B' | names == 'C';    % indices of ending nodes
    distances = Inf(size(names));    % initialize distances to infinity
    distances(start_node) = zeros(1);    % distance from start node to itself is zero
    visited = false(size(names));    % initialize visited array to false
    
    % Run Dijkstra's algorithm
    while ~all(visited(end_nodes))
    % Find unvisited node with smallest tentative distance
    [~, current_node] = min(distances(~visited));
    
    % Mark current node as visited
    visited(current_node) = true;
    
    % Update distances for neighbors of current node
    for neighbor = find(A1(current_node,:))
        if ~visited(neighbor)
            new_distance = distances(current_node) + A1(current_node,neighbor);
            if new_distance < distances(neighbor)
                distances(neighbor) = new_distance;
            end
        end
    end
    end
    
    % Print shortest distances to ending nodes
    fprintf('Shortest distances to ending nodes:\n');
    for i = find(end_nodes)
        fprintf('%s: %d\n', names{i}, distances(i));
    end
    
    % Find shortest path to B and C
    if distances(names == 'B') < distances(names == 'C')
        shortest_path = {'A' 'B'};
    else
        shortest_path = {'A' 'C'};
    end
    
    % Print shortest path
    fprintf('Shortest path: %s', shortest_path{1});
    for i = 2:length(shortest_path)
        fprintf(' -> %s', shortest_path{i});
    end
    fprintf('\n');

this is error

start_node = names == 'A'; % index of starting node

↑

Error: Incorrect use of '=' operator. To assign a value to a variable, use '='. To compare values for equality,

use '=='.

Answer 1

[Aman]

Hi there,

In the line,

start_node = names == 'A';

You are trying to use '==' operator on names which is a cell array and cell arrays do not support '==' operations. Since names only contains character data type, so you can define them using array as follow:

names = ['1' '2' '3' '4' '5' '6' '7' '8' 'A' 'B' 'C'];

Hope it helps!