C get element nodes of edge segments

In C, you can get the element nodes of edge segments by using the mesh data structure. Here's an example code snippet:

#include <stdio.h>

// Define the mesh data structure
typedef struct {
    int node1;
    int node2;
    int element;
} EdgeSegment;

typedef struct {
    int node;
} ElementNode;

// Function to get the element nodes of edge segments
void getElementNodes(EdgeSegment* edgeSegments, int numSegments, ElementNode* elementNodes, int numNodes) {
    // Iterate over each edge segment
    for (int i = 0; i < numSegments; i++) {
        EdgeSegment edgeSegment = edgeSegments[i];
        int elementIndex = edgeSegment.element;

        // Check if the element index is within the valid range
        if (elementIndex >= 0 && elementIndex < numNodes) {
            // Add the element node to the array
            elementNodes[elementIndex].node = edgeSegment.node1;
            elementNodes[elementIndex + 1].node = edgeSegment.node2;
        }
    }
}

int main() {
    // Example data
    EdgeSegment edgeSegments[] = {
        {1, 2, 0},
        {2, 3, 1},
        {3, 4, 2}
    };
    int numSegments = sizeof(edgeSegments) / sizeof(EdgeSegment);

    ElementNode elementNodes[3]; // Assuming 3 element nodes
    int numNodes = sizeof(elementNodes) / sizeof(ElementNode);

    // Get the element nodes of edge segments
    getElementNodes(edgeSegments, numSegments, elementNodes, numNodes);

    // Print the element nodes
    for (int i = 0; i < numNodes; i++) {
        printf("Element node %d: %d\n", i, elementNodes[i].node);
    }

    return 0;
}

This code defines a mesh data structure using EdgeSegment and ElementNode structs. The getElementNodes function takes an array of EdgeSegment objects, the number of segments, an array of ElementNode objects, and the number of nodes. It iterates over each edge segment, checks if the element index is within the valid range, and adds the element nodes to the array. Finally, the code prints the element nodes