C not C++

The program deals with linked lists. Each node of such a list contains a string of length at most 255, a positive integer (i.e., an integer value 1) and a pointer to the next node of the list. For any node, the string and the integer stored in that node will be referred to as the text and the index for that node respectively. Initially, the list is empty. At all times, the existing list must satisfy the following requirements:

1.The index is a number of the node in the list, i.e. the first node has index 1, and when the list is scanned from the beginning to the end, the value of indexes is increasing by 1.

2.The texts appearing in the list are all distinct; that is, no two nodes have the same text.

Functions: InsertAfterIndex, InsertBeforeIndex, ReplaceNodeWithcertain index, deleteNodeWithIndex