实验5

时间：2019-05-26 17:47:43 阅读：101 评论：0 收藏：0 [点我收藏+]

标签：字典序 sea binary oid temp sort dex void 回忆

1.二分查找

ex1-1

#include <stdio.h>
const int N=9;
int binarySearch(int x[], int n, int item);
int main() {
    int a[N]={1,3,7,9,16,21,33,44,57};
    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); 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;
}

技术图片

ex-1-2

#include <stdio.h>
const int N=9;
int binarySearch(int *x, int n, int item);
int main() {
    int a[N]={1,3,9,16,21,44,57,88,97};
    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); 
        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;
}

技术图片

选择法排序

ex2-2

#include <stdio.h>
#include <string.h>
void selectSort(char str[][20], int n );
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);
printf("按字典序输出名单:\n");
    for(i=0; i<5; i++)
printf("%s\n", name[i]);
return 0;
}
void selectSort(char str[][20], int n) {
int i,j,k;
char temp[20];
for(i=0;i<n-1;i++){ 
    k=i;
   for(j=i+1;j<n;j++)
    if(strcmp(str[k],str[j])>0)
    k=j;
    
    if(k!=i){
    strcpy(temp,str[i]);
    strcpy(str[i],str[k]);
    strcpy(str[k],temp);}
            
    }


}