1．建立顺序查找表，并在此查找表上实现顺序查找操作。 2．建立有序顺序查找表，并在此查找表上实现二分查找操作。c语言

1. 顺序查找表的实现：

#include <stdio.h>
#define MAXSIZE 100

typedef struct {
    int key;
    char data;
} Element;

typedef struct {
    Element elem[MAXSIZE];
    int length;
} SeqList;

int SeqSearch(SeqList *L, int key) {
    int i;
    for (i = 0; i < L->length; i++) {
        if (L->elem[i].key == key) {
            return i;
        }
    }
    return -1;
}

int main() {
    SeqList L = {
        {{1,'a'},{3,'b'},{5,'c'},{7,'d'},{9,'e'}}, 5
    };
    int i, key, pos;
    printf("请输入查找的关键字：");
    scanf("%d", &key);
    pos = SeqSearch(&L, key);
    if (pos == -1) {
        printf("未找到关键字为%d的数据\n", key);
    } else {
        printf("关键字为%d的数据在顺序表中的位置为：%d\n", key, pos);
    }
    return 0;
}

2. 有序顺序查找表的实现：

#include <stdio.h>
#define MAXSIZE 100

typedef struct {
    int key;
    char data;
} Element;

typedef struct {
    Element elem[MAXSIZE];
    int length;
} SeqList;

int BinarySearch(SeqList *L, int key) {
    int low = 0, high = L->length - 1, mid;
    while (low <= high) {
        mid = (low + high) / 2;
        if (L->elem[mid].key == key) {
            return mid;
        } else if (L->elem[mid].key > key) {
            high = mid - 1;
        } else {
            low = mid + 1;
        }
    }
    return -1;
}

int main() {
    SeqList L = {
        {{1,'a'},{3,'b'},{5,'c'},{7,'d'},{9,'e'}}, 5
    };
    int i, key, pos;
    printf("请输入查找的关键字：");
    scanf("%d", &key);
    pos = BinarySearch(&L, key);
    if (pos == -1) {
        printf("未找到关键字为%d的数据\n", key);
    } else {
        printf("关键字为%d的数据在顺序表中的位置为：%d\n", key, pos);
    }
    return 0;
}