请问如何在主函数中调取我的交换函数

#include"stdio.h"
#include"stdlib.h"
#define INIT_SIZE 5
#define INCREMENT 2
typedef int ElemType;
typedef struct {
ElemType* elem;
int length;
int listsize;
}SqList;
int InitList_Sq(SqList* L)
{
L->elem = (ElemType*)malloc(INIT_SIZE * sizeof(ElemType));
if (!L->elem)return -1;
L->length = 0;
L->listsize = INIT_SIZE;
return 1;
}//初始化
int ListInsert_Sq(SqList* L, int i, ElemType e)
{
ElemType* newbase;
int j;
if (i<1 || i>L->length + 1)return -1;
if (L->length == L->listsize)
{
newbase = (ElemType*)realloc(L->elem, (L->listsize + INCREMENT) * sizeof(ElemType));
if (newbase == NULL)return -1;
L->elem = newbase;
L->listsize += INCREMENT;
}
for (j = L->length - 1; j >= i - 1; j--) {
L->elem[j + 1] = L->elem[j];
}
L->elem[i - 1] = e;
L->length++;
return 0;
}//插入
int ListDelete_Sq(SqList* L, int i)
{
int j;
if (i < 1 || i >L->length)
return -1;
for (j = i; j < L->length; j++) {
L->elem[j - 1] = L->elem[j];
}
L->length--;
return 0;
}//删除
int LocateElem_Sq(SqList L, ElemType e)
{
int i;
for (i = 0; i < L.length; i++) {
if (L.elem[i] == e)
return i + 1;
}
return 0;
}//查找
void output(SqList L) {
int i;
for (i = 0; i < L.length; i++)
{
printf("%d\t", L.elem[i]);
}
printf("\n");
}//输出
int MergeList_Sq(SqList LA, SqList LB, SqListLC)
{
int i = 0, j = 0, k = 0;
LC->listsize = LA.length + LB.length;
LC->elem = (ElemType)malloc(LC->listsize * sizeof(ElemType));
if (!LC->elem)return -1;
while (i < LA.length && j < LB.length) {
if (LA.elem[i] <= LB.elem[j])LC->elem[k++] == LA.elem[i++];
else LC->elem[k++] = LB.elem[j++];
}
while (i < LA.length) LC->elem[k++] = LA.elem[i++];
while (i < LB.length) LC->elem[k++] = LB.elem[i++];
LC->length = k;
return 1;
}//交换
void main() {
SqList L,T,R;
InitList_Sq(&L);
InitList_Sq(&T);
ListInsert_Sq(&L, 1, 1);
ListInsert_Sq(&L, 2, 2);
ListInsert_Sq(&T, 1, 3);
ListInsert_Sq(&T, 2, 4);
MergeList_Sq();
output(R);
}