查找

顺序表的顺序及二分查找：

#include<stdio.h>
#include<stdlib.h>


typedef int Position;
typedef int ElementType;
typedef struct LNode *PtrToLNode;

#define MAXSIZE 10

struct LNode{
    ElementType Data[MAXSIZE];
    Position Last;
};
typedef PtrToLNode List;

List MakeEmpty(){
    List P;
    P = (List)malloc(sizeof(struct LNode));
    P->Last = -1;
    return P;
}

bool Insert(List L,Position n,ElementType x){
    if(L->Last == MAXSIZE - 1)
    {
        printf("表满");
        return false;
    }
    if(n<1 || n>L->Last+1+1){
        printf("位序不合法");
        return false;
    }
    for(int j = L->Last;j>=n-1;j--)
    {
        L->Data[j+1] = L->Data[j];
    }
    L->Data[n-1] = x;
    L->Last++;
    return true;
}



bool Delete(List L,Position n){
        if(L->Last == MAXSIZE - 1)
    {
        printf("表满");
        return false;
    }
    if(n<1 || n>L->Last+1){
        printf("位序不合法");
        return false;
    }
    for(int j = n-1;j<L->Last+1;j++)
    {
        L->Data[j] = L->Data[j+1];
    }
    L->Last--;
    return true;

}



int Length(List L){
    return L->Last+1;
} 

int Printf(List L){
    for(int i = 0 ; i<L->Last+1;i++)
        printf("%d  ",L->Data[i]);
    printf("\n");
    return 0;
}

//=======查找=======

Position Find(List L,ElementType x){
    int j;
    for( j = 0;j<L->Last+1;j++)
    {
        if(x == L->Data[j])
        {    
            printf("查找的下表%d位序为：%d\n",L->Data[j],j+1);
            return 0;
        }
    }
    if(j >= L->Last)
    {
        printf("查找的不存在");
    }
    return 0;
        
}

//=======顺序查找=======

Position SequentialSerch(List Tb1,ElementType K){
    Position i;
    Tb1->Data[0] = K;
    for(i = Tb1->Last;Tb1->Data[i] != K;i--);

    return i+1;


}

//=======二分查找=======

Position BinarySearch(List Tb1,ElementType K){
    Position left,right,mid;

    left = 1;
    mid = 0;
    right = Tb1->Last;
    while(left<=right){
        mid = (left + right)/2;
        if( K < Tb1->Data[mid])
            right = mid-1;
        else if(K>Tb1->Data[mid])
            left = mid+1;
        else
            return mid+1;
    }
    return 0;

}

int main(){
    List L;
    L = MakeEmpty();
    for(int i =1;i<11;i++)
        Insert(L,i,i);
    Printf(L);
    printf("表长：%d\n",Length(L));

    Find(L,4);
    printf("顺序查找4的位置为：%d\n",SequentialSerch(L,4));
    printf("二分查找4的位置为：%d\n",BinarySearch(L,4));

    return 0;

}