实验五
//task1
#include <stdio.h> #define N 5 void output(int x[], int n); int main() { int x[] = {9, 55, 30, 27, 22}; int i; int k; int t; printf("original array:\n"); output(x,N); k = 0; for(i=1;i<N;++i) if(x[i]>x[k]) k = i; if(k != N-1); { t = x[N-1]; x[N-1] = x[k]; x[k] = t; } printf("after swapped:\n"); output(x,N); return 0; } void output(int x[], int n) { int i; for(i = 0;i<n;++i) printf("%d",x[i]); printf("\n"); }
//task1.2 #include <stdio.h> #define N 5 void output(int x[], int n); int main() { int x[] = {9, 55, 30, 27, 22}; int i; int t; printf("original array:\n"); output(x,N); for(i=0;i<N-1;++i) if(x[i]>x[i+1]) { t = x[i]; x[i] = x[i+1]; x[i+1] = t; } printf("after swapped:\n"); output(x,N); return 0; } void output(int x[], int n) { int i; for(i = 0;i<n;++i) printf("%d",x[i]); printf("\n"); }
//task 2 #include <stdio.h> #define N 5 int binarysearch(int x[], int n, int item); int main() { int a[N] = {2,7,19,45,66}; 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); 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(x[mid]==item) return mid; else if(x[mid]>item) high = mid - 1; else low = mid + 1; } return -1; }
//task 3 #include<stdio.h> #define N 5 void selectsort(int a[],int n); void input(int a[],int n); void output(int a[],int n); int main(){ int a[N]; printf("输入%d个整数\n",N); input(a,N); printf("排序前的数据:\n"); output(a,N); selectsort(a,N); printf("排序后的数据:\n"); output(a,N); return 0; } void input(int a[],int n){ int i; for(i=0;i<n;i++){ scanf("%d",&a[i]); } } void output(int a[],int n){ int i; for(i=0;i<n;i++){ printf("%d ",a[i]); } printf("\n"); } void selectsort(int a[],int n){ int i,j,k,temp; for(i=0;i<n-1;i++){ k=i;//k用于记录当前最小元素的下标 for(j=i+1;j<n;j++){ if(a[j]<a[k]) k=j; } if(k!=i){ temp=a[i]; a[i]=a[k]; a[k]=temp; } } }
//task 4 #include <stdio.h> #include<string.h> #define N 5 void selectsort(char str[][20],int n); int main() { char name[][20] = {"Bob","Bill","Joseph","Taylor","George"}; int i; printf("输入初始名单:\n"); for(i = 0;i<N;i++) printf("%s\n",name[i]); selectsort(name,N); printf("按字典序输出名单:\n"); for(i = 0;i<N;i++) printf("%s\n",name[i]); return 0; } void selectsort(char str[][20], int n) { int i, j; char temp[20]; for(i = 0;i<n - 1;i++) { for(j = i+1;j<n;j++) { if(strcmp(str[j],str[i])<0) { strcpy(temp,str[j]); strcpy(str[j],str[i]); strcpy(str[i],temp); } } } }
//task 5 #include<stdio.h> int main() { int n; int *pn; n = 42; pn =&n; printf("&n = %#x, n = %d\n", &n, n); printf("&pn = %#x,pn = %#x\n",&pn,pn); printf("*pn = %d\n",*pn); return 0; }
//task 6 #include <stdio.h> #define N 5 int main() { int a[N] = {1,9,2,0,7}; int i; int *p; for(i = 0;i<N;i++) printf("&a[%d] = %#x, a[&d] = %d\n",i,&a[i],i,a[i]); printf("\n"); for(i = 0; i<N;i++) printf("a+%d = %#x, *(a+%d) = %d\n",i,a+i,i,*(a+i)); printf("\n"); p = a; for(i = 0;i<N;++i) printf("p+%d = %#x, *(p+%d) = %d\n",i,p+i,i,*(p+i)); return 0; }