我想实现数据的插入，删除和修改，求修改代码让他能成功运行

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct SPB
{
int seller_num;
int fit_num;
int building_num;
int count;
struct SPB* next;
}ListNode, * LinkList;
int main()
{
struct SPB* head = (struct SPB*)malloc(sizeof(struct SPB));
if (head == NULL)
{
printf("分配失败，程序结束");
exit(0);
}
head->next = NULL;
struct SPB* p = NULL;
int ch = 0;
while (ch != 5)
{
printf("\nMUNU\n");//菜单
printf("add data---------1\n");
printf("delete data------2\n");
printf("update data------3\n");
printf("print linklist---4\n");
printf("exit ------------5\n");
printf("***************\n\n");
printf("请输入你的选择:");
scanf("%d", &ch);
if (ch == 1)
{
struct SPB pb; //struct SPB pf, * pb;
int i;
if (head == NULL)
continue;
else {
p = head;
while (p->next) p = p->next;
}
for (i = 0; i < 2; i++)
{
pb = (struct SPB*)malloc(sizeof(struct SPB));
if (NULL == pb)
{
printf("malloc fail!\n");
break; //return head;
}
pb->next = NULL;
printf("\nseller's number: ");
scanf("%d", &pb->seller_num);
printf("fit's number: ");
scanf("%d", &pb->fit_num);
printf("builiding's number: ");
scanf("%d", &pb->building_num);
printf("count's number: ");
scanf("%d", &pb->count);
p->next = pb;
p = pb;
}
}
if (ch == 2)
{
int i, j = 0;
struct SPB q = NULL;
if (head == NULL)
continue;
else {
p = head;
}
do {
printf("请输入需删除的项:");
scanf("%d", &i);
} while (i <= 0);
while (p && j < i)
{
q = p;
p = p->next;
j++;
}
if (p == NULL)
printf("\n未找到删除的项.\n");
else {
q->next = p->next;
free(p);
printf("\n第%d项删除成功.\n", i);
}
}
if (ch == 3)
{
int i, j = 0;
if (head == NULL)
continue;
else {
p = head;
}
do {
printf("请输入需修改的项:");
scanf("%d", &i);
} while (i <= 0);
while (p && j < i)
{
p = p->next;
j++;
}
if (p == NULL)
printf("\n未找到修改的项.\n");
else {
int sel;
do{
printf("\n请输入你要修改的数据 1,销售商号码 2,配件号 3,工地号 4,数量 :");
scanf("%d", &sel);
} while (sel < 1 || sel>4);
switch (sel) {
case 1:printf("请输入新的销售商品号：");
scanf("%d", &p->seller_num);
break;
case 2:printf("请输入新的配件号：");
scanf("%d", &p->fit_num);
break;
case 3:printf("请输入新的工地号：");
scanf("%d", &p->building_num);
break;
case 4:printf("请输入新的数量：");
scanf("%d", &p->count);
break;
default:break;
}
printf("\n第%d项数据修改成功.\n", i);
}
}
if (ch == 4)
{
if (head->next == NULL)
continue;
else {
p = head->next;
}
printf("\n1.销售商号码\t2.配件号\t3.工地号\t4.数量\n");
while (p)
{
printf("%d\t\t%d\t\t%d\t\t%d\n", p->seller_num, p->fit_num, p->building_num, p->count);
p = p->next;
}
}
}
return 0;
}

修改如下，供参考：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct SPB
{
    int seller_num;
    int fit_num;
    int building_num;
    int count;
    struct SPB* next;
}ListNode, * LinkList;
int main()
{
    struct SPB* head = (struct SPB*)malloc(sizeof(struct SPB));
    if (head == NULL)
    {
        printf("分配失败，程序结束");
        exit(0);
    }
    head->next = NULL;
    struct SPB* p = NULL;
    int ch = 0;
    while (ch != 6)
    {
        printf("\n*******MUNU*******\n");//菜单
        printf("add data---------1\n");  //增加 
        printf("delete data------2\n");  //删除 
        printf("update data------3\n");  //修改
        printf("insert data------4\n");  //插入
        printf("print linklist---5\n");  //输出 
        printf("exit ------------6\n");  //退出
        printf("******************\n\n");
        printf("请输入你的选择:");
        scanf("%d", &ch);
        if (ch == 1)
        {
            struct SPB* pb; //struct SPB* pf, * pb;
            int i;
            if (head == NULL) 
                continue;
            else {
                p = head;
                while (p->next) p = p->next;
            }
            for (i = 0; i < 2; i++)
            {
                pb = (struct SPB*)malloc(sizeof(struct SPB));
                if (NULL == pb)
                {
                    printf("malloc fail!\n");
                    break; //return head;
                }
                pb->next = NULL;
                printf("\nseller's number: ");
                scanf("%d", &pb->seller_num);
                printf("fit's number: ");
                scanf("%d", &pb->fit_num);
                printf("builiding's number: ");
                scanf("%d", &pb->building_num);
                printf("count's number: ");
                scanf("%d", &pb->count);
                p->next = pb;
                p = pb;
            }
        }
        if (ch == 2) 
        {
            int i, j = 0;
            struct SPB* q = NULL;
            if (head == NULL)
                continue;
            else {
                p = head;
            }
            do {
                printf("请输入需删除的项:");
                scanf("%d", &i); 
            } while (i <= 0);
            while (p && j < i)
            {
                q = p;
                p = p->next;
                j++;
            }
            if (p == NULL)
                printf("\n未找到删除的项.\n");
            else {
                q->next = p->next;
                free(p);
                printf("\n第%d项删除成功.\n", i);
            }
        }
        if (ch == 3)
        {
            int i, j = 0;
            if (head == NULL)
                continue;
            else {
                p = head;
            }
            do {
                printf("请输入需修改的项:");
                scanf("%d", &i); 
            } while (i <= 0);
            while (p && j < i)
            {
                p = p->next;
                j++;
            }
            if (p == NULL)
                printf("\n未找到修改的项.\n");
            else {
                int sel;
                do{
                    printf("\n请输入你要修改的数据 1,销售商号码 2,配件号 3,工地号 4,数量 :");
                    scanf("%d", &sel);
                } while (sel < 1 || sel>4);
                switch (sel) {
                case 1:printf("请输入新的销售商品号：");
                       scanf("%d", &p->seller_num);
                       break;
                case 2:printf("请输入新的配件号：");
                       scanf("%d", &p->fit_num);
                       break;
                case 3:printf("请输入新的工地号：");
                       scanf("%d", &p->building_num);
                       break;
                case 4:printf("请输入新的数量：");
                       scanf("%d", &p->count);
                       break;
                default:break;
                }
                printf("\n第%d项数据修改成功.\n", i);
            }
        }
        if (ch == 4)
        {
            int i, j = 0;
            if (head == NULL)
                continue;
            else {
                p = head;
            }
            struct SPB* q = NULL, * ib = (struct SPB*)malloc(sizeof(struct SPB));
            ib->next = NULL;
            do {
                printf("请输入插入的项序号（前插）:");
                scanf("%d", &i);
            } while (i <= 0);
            printf("\n请输入插入项的数据:\n");
            printf("\nseller's number: ");
            scanf("%d", &ib->seller_num);
            printf("fit's number: ");
            scanf("%d", &ib->fit_num);
            printf("builiding's number: ");
            scanf("%d", &ib->building_num);
            printf("count's number: ");
            scanf("%d", &ib->count);
            while (p && j < i)
            {
                q = p;
                p = p->next;
                j++;
            }
            if (p == NULL)
                q->next = ib;  
            else {
                ib->next = q->next;
                q->next  = ib;
            }
            printf("\n第%d项插入成功.\n", i);
        }
        if (ch == 5)
        {
            if (head->next == NULL)
                continue;
            else {
                p = head->next;
            }
            printf("\n1.销售商号码\t2.配件号\t3.工地号\t4.数量\n");
            while (p)
            {
                printf("%d\t\t%d\t\t%d\t\t%d\n", p->seller_num, p->fit_num, p->building_num, p->count);
                p = p->next;
            }
        }
    }
    return 0;
}

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct SPB
{
int seller_num;
int fit_num;
int building_num;
int count;
struct SPB* next;
}ListNode, * LinkList;
int main()
{
struct SPB* head = (struct SPB*)malloc(sizeof(struct SPB));
if (head == NULL)
{
printf("分配失败，程序结束");
exit(0);
}
head->next = NULL;
struct SPB* p = NULL;
int ch = 0;
while (ch != 5)
{
printf("\nMUNU\n");//菜单
printf("add data---------1\n");
printf("delete data------2\n");
printf("update data------3\n");
printf("print linklist---4\n");
printf("exit ------------5\n");
printf("***************\n\n");
printf("请输入你的选择:");
scanf("%d",&ch);
if (ch == 1)
{
struct SPB *pb; //struct SPB pf, * pb;
int i;
if (head == NULL)
continue;
else {
p = head;
while (p->next) p = p->next;
}
for (i = 0; i < 2; i++)
{
pb = (struct SPB*)malloc(sizeof(struct SPB));
if (NULL == pb)
{
printf("malloc fail!\n");
break; //return head;
}
pb->next = NULL;
printf("\nseller's number: ");
scanf("%d", &pb->seller_num);
printf("fit's number: ");
scanf("%d", &pb->fit_num);
printf("builiding's number: ");
scanf("%d", &pb->building_num);
printf("count's number: ");
scanf("%d", &pb->count);
p->next = pb;
p = pb;
}
}
if (ch == 2)
{
int i, j = 0;
struct SPB *q = NULL;
if (head == NULL)
continue;
else {
p = head;
}
do {
printf("请输入需删除的项:");
scanf("%d", &i);
} while (i <= 0);
while (p && j < i)
{
q = p;
p = p->next;
j++;
}
if (p == NULL)
printf("\n未找到删除的项.\n");
else {
q->next = p->next;
free(p);
printf("\n第%d项删除成功.\n", i);
}
}
if (ch == 3)
{
int i, j = 0;
if (head == NULL)
continue;
else {
p = head;
}
do {
printf("请输入需修改的项:");
scanf("%d", &i);
} while (i <= 0);
while (p && j < i)
{
p = p->next;
j++;
}
if (p == NULL)
printf("\n未找到修改的项.\n");
else {
int sel;
do {
printf("\n请输入你要修改的数据 1,销售商号码 2,配件号 3,工地号 4,数量 :");
scanf("%d", &sel);
} while (sel < 1 || sel>4);
switch (sel) {
case 1:printf("请输入新的销售商品号：");
scanf("%d", &p->seller_num);
break;
case 2:printf("请输入新的配件号：");
scanf("%d", &p->fit_num);
break;
case 3:printf("请输入新的工地号：");
scanf("%d", &p->building_num);
break;
case 4:printf("请输入新的数量：");
scanf("%d", &p->count);
break;
default:break;
}
printf("\n第%d项数据修改成功.\n", i);
}
}
if (ch == 4)
{
if (head->next == NULL)
continue;
else {
p = head->next;
}
printf("\n1.销售商号码\t2.配件号\t3.工地号\t4.数量\n");
while (p)
{
printf("%d\t\t%d\t\t%d\t\t%d\n", p->seller_num, p->fit_num, p->building_num, p->count);
p = p->next;
}
}
}
return 0;
}

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct SPB
{
    int seller_num;
    int fit_num;
    int building_num;
    int count;
    struct SPB* next;
}ListNode, * LinkList;
int main()
{
    struct SPB* head = (struct SPB*)malloc(sizeof(struct SPB));
    if (head == NULL)
    {
        printf("分配失败，程序结束");
        exit(0);
    }
    head->next = NULL;
    struct SPB* p = NULL;
    int ch = 0;
    while (ch != 5)
    {
        printf("\nMUNU\n");//菜单
        printf("add data---------1\n");
        printf("delete data------2\n");
        printf("update data------3\n");
        printf("print linklist---4\n");
        printf("exit ------------5\n");
        printf("***************\n\n");
        printf("请输入你的选择:");
        scanf("%d", &ch);
        if (ch == 1)
        {
            struct SPB* pb; //struct SPB pf, * pb;
            int i;
            if (head == NULL)
                continue;
            else {
                p = head;
                while (p->next) p = p->next;
            }
            for (i = 0; i < 2; i++)
            {
                pb = (struct SPB*)malloc(sizeof(struct SPB));
                if (NULL == pb)
                {
                    printf("malloc fail!\n");
                    break; //return head;
                }
                pb->next = NULL;
                printf("\nseller's number: ");
                scanf("%d", &pb->seller_num);
                printf("fit's number: ");
                scanf("%d", &pb->fit_num);
                printf("builiding's number: ");
                scanf("%d", &pb->building_num);
                printf("count's number: ");
                scanf("%d", &pb->count);
                p->next = pb;
                p = pb;
            }
        }
        if (ch == 2)
        {
            int i, j = 0;
            struct SPB* q = NULL;
            if (head == NULL)
                continue;
            else {
                p = head;
            }
            do {
                printf("请输入需删除的项:");
                scanf("%d", &i);
            } while (i <= 0);
            while (p && j < i)
            {
                q = p;
                p = p->next;
                j++;
            }
            if (p == NULL)
                printf("\n未找到删除的项.\n");
            else {
                q->next = p->next;
                free(p);
                printf("\n第%d项删除成功.\n", i);
            }
        }
        if (ch == 3)
        {
            int i, j = 0;
            if (head == NULL)
                continue;
            else {
                p = head;
            }
            do {
                printf("请输入需修改的项:");
                scanf("%d", &i);
            } while (i <= 0);
            while (p && j < i)
            {
                p = p->next;
                j++;
            }
            if (p == NULL)
                printf("\n未找到修改的项.\n");
            else {
                int sel;
                do {
                    printf("\n请输入你要修改的数据 1,销售商号码 2,配件号 3,工地号 4,数量 :");
                    scanf("%d", &sel);
                } while (sel < 1 || sel>4);
                switch (sel) {
                case 1:printf("请输入新的销售商品号：");
                    scanf("%d", &p->seller_num);
                    break;
                case 2:printf("请输入新的配件号：");
                    scanf("%d", &p->fit_num);
                    break;
                case 3:printf("请输入新的工地号：");
                    scanf("%d", &p->building_num);
                    break;
                case 4:printf("请输入新的数量：");
                    scanf("%d", &p->count);
                    break;
                default:break;
                }
                printf("\n第%d项数据修改成功.\n", i);
            }
        }
        if (ch == 4)
        {
            if (head->next == NULL)
                continue;
            else {
                p = head->next;
            }
            printf("\n1.销售商号码\t2.配件号\t3.工地号\t4.数量\n");
            while (p)
            {
                printf("%d\t\t%d\t\t%d\t\t%d\n", p->seller_num, p->fit_num, p->building_num, p->count);
                p = p->next;
            }
        }
    }
    return 0;
}