please help me with these questions! thank you!(in C language)

1. [10] Write a function ini search_substring(char texall, int tlen, char pattern (), int plen, int **index, int *ilen) to find if pattem exists in text, where text and pattern are two arrays and plen tlen. The function returns all the indices of j of text in array index/] if text/j...j+plen-1] - pattern[O...plen-1), ilen is initialized to 0. and the array index is dynarically allocated, please also write a function call example, 2.[10] Assume the node structure is as follows: struct node { int data; struct node *next; struct node *prev; please write a function struct node *merge(struct node *a. struct node "h) to merge two doubly linked lists contains integer numbers without duplicates in the increasing order. You have to remove duplicates. Also show how to call this function. 3. [15] Assume a sparse 2-D nxn matrice uses the following linked list data structure to save memory when n is large. Write a nor-recursive fur ction to : ultiply two 2-D nxn ratrices. struct node { int x, y: [800 11] int value; struct node "right, down; 0 1 0 0 00012 22 0 15 0