实验5

#include  <stdio.h>
const int N=5;
int binarySearch(int x[], int n, int item);
int main() {
    int a[N]={1,5,9,13,26};
    int i,index, key;
     
    printf("数组a中的数据:\n");
    for(i=0;i<N;i++)
       printf("%d ",a[i]);
    printf("\n");
     
    printf("输入待查找的数据项: ");
    scanf("%d", &key);
     
    index = binarySearch(a, N, key);
     
     
    if(index>=0)
        printf("%d在数组中，下标为%d\n", key, index);
    else
        printf("%d不在数组中\n", key);
    getchar();
   return 0;
}
int binarySearch(int x[], int n, int item) {
    int low, high, mid;
     
    low = 0;
    high = n-1;
     
    while(low <= high) {
        mid = (low+high)/2;
         
        if (item == x[mid])
            return mid;
        else if(item<x[mid])
            high = mid - 1;
        else
            low = mid + 1;
    }
     
    return -1;
}

#include  <stdio.h>
const int N=5;
int binarySearch(int x[], int n, int item);
int main() {
    int a[N]={1,5,9,13,26};
    int i,index, key;
     
    printf("数组a中的数据:\n");
    for(i=0;i<N;i++)
       printf("%d ",a[i]);
    printf("\n");
     
    printf("输入待查找的数据项: ");
    scanf("%d", &key);
     
    index = binarySearch(a, N, key);
     
     
    if(index>=0)
        printf("%d在数组中，下标为%d\n", key, index);
    else
        printf("%d不在数组中\n", key);
    getchar();
   return 0;
}
int binarySearch(int x[], int n, int item) {
    int low, high, mid;
     
    low = 0;
    high = n-1;
     
    while(low <= high) {
        mid = (low+high)/2;
         
        if (item == x[mid])
            return mid;
        else if(item<x[mid])
            high = mid - 1;
        else
            low = mid + 1;
    }
     
    return -1;
}

#include <stdio.h>
#include <string.h>
void selectSort(char str[][20], int n ); // 函数声明，形参str是二维数组名
int main() {
    char name[][20] = {"John", "Alex", "Joseph", "Candy", "Geoge"};
    int i;
     
    printf("输出初始名单:\n");
    for(i=0; i<5; i++)
        printf("%s\n", name[i]);
         
    selectSort(name, 5);  // 调用选择法对name数组中的字符串排序
     
    printf("按字典序输出名单:\n");
    for(i=0; i<5; i++)
        printf("%s\n", name[i]);
      
    return 0;
}
 
// 函数定义
// 函数功能描述：使用选择法对二维数组str中的n个字符串按字典序排序
void selectSort(char str[][20], int n) {
    int i,j;
    char t[20];
    for(i=0;i<n-1;i++)
      for(j=0;j<n-i-1;j++)
      {
          if(strcmp(str[j],str[j+1])>0)
          {
              strcpy(t,str[j]);
            strcpy(str[j],str[j+1]);
            strcpy(str[j+1],t);
           }      
      }
     
    }