元素插入顺序表

线性表(a1,a2,a3,...,an)中元素递增有序且按顺序存储于计算机内,要求设计一算法完成:

1)用最少时间在表中查找元素数值为x的元素

2)若找到将其与后继元素位置相交换

3)若找不到将其插入表中并使表中元素仍然递增有序

#include <stdio.h>
#define N 8
#define ElemType int
int SearchExchangeInsert(ElemType a[],ElemType x)
{
    int low,high,mid,i;
    low = 0,high = N-2;
    while(low <= high)
    {
        mid = (low + high)/2;
        if(a[mid] == x)
            break;
        else if(a[mid] < x){
            low = mid + 1;
        }
        else{
            high = mid -1;
        }
    }
    if(a[mid] == x && mid != N-2)//若最后一个元素与x相等,则不存在与其后继交换的操作
    {
        a[mid] = a[mid+1] - a[mid] + (a[mid+1] = a[mid]);
    }
    if(low > high)//查找失败,插入元素x
    {
        for(i=N-2;i>high;i--)//a[high] < x,high之后都比x大
            a[i+1] = a[i];
        a[i+1] = x;
        return 1;
    }
    return 0;
}
int main()
{
    ElemType a[N] = {1,4,7,10,20,23,25};//默认最后一个数为0
    ElemType x = 26;//0,1,3,8,25,26
    if(SearchExchangeInsert(a,x))//x插入表中
        for(int i=0;i<N;i++)
            printf("%d,",a[i]);
    else{
        for(int i=0;i<N-1;i++)
            printf("%d,",a[i]);
    }
    return 0;
}