慕課-程式設計與演算法(大學先修課)-郭煒-第八九周練習題
阿新 • • 發佈:2019-02-17
1.下面程式片段的輸出結果是 Hello ,請填空
#include <iostream>
using namespace std;
int main() {
char s[] = "Hello";
char * p;
for(p=s;*p!=NULL;p++)
cout << * p ;
return 0;
}
2.下面程式輸出結果是 Tesla Tes 請填空
#include <iostream>
using namespace std;
void Print(const char * p1, const char * p2)
{
for(;p1<p2;p1++)
cout << * p1;
}
int main()
{
const char * s = "Tesla123";
Print(s,s+5);
cout << endl;
Print(s,s+3);
cout << endl;
return 0;
}
3.程式填空,使得輸出結果為:
1,4,9,16,25,
h,e,l,l,o,!,
#include <iostream>
using namespace std;
void ForEach(void * a, int width, int num,
void f(void *)
)
{
for(int i = 0;i < num; ++i)
f((char*)a+width*i);
}
void PrintSquare(void * p)
{
int * q = (int*)p;
int n = *q;
cout << n * n << ",";
}
void PrintChar(void * p) {
char * q = (char *)p;
cout << *q << ",";
}
int main()
{
int a[5] = {1,2,3,4,5};
char s[] = "hello!";
ForEach(a,sizeof(int),5,PrintSquare);
cout << endl;
ForEach(s,sizeof(char),6,PrintChar);
return 0;
}
4.Memcpy之一
輸入:
第一行是整數t
接下來是t個整數
再接下來是t個不帶空格的字串,長度不超過20
輸出:
按原樣輸出t個整數和t個字串
#include <iostream>
using namespace std;
void Memcpy(char * src,char * dest,int n)
{
for(int i=0;i<n;i++)
{
dest[i]=src[i];
}
}
int Strlen(char * s)
{
int i;
for( i = 0; s[i]; ++i);
return i;
}
int main()
{
int a;
char s1[30];
char s2[30];
int t;
cin >> t;
for(int i = 0;i < t; ++i) {
cin >> a;
int b = 99999999;
Memcpy((char*)&a,(char *) &b,sizeof(int));
cout << b << endl;
}
for(int i = 0;i < t; ++i) {
cin >> s1;
Memcpy(s1,s2,Strlen(s1)+1);
cout << s2 << endl;
}
return 0;
}
5.程式填空,使其輸出結果是: 1,2,3,4, 10,12,14,16, 18,20,11,12,
#include <iostream>
using namespace std;
void Double(int * p, int n)
{
for(int i = 0;i < n; ++i)
p[i] *= 2;
}
int main()
{
int a[3][4] = { { 1,2,3,4},{5,6,7,8},
{ 9,10,11,12 } };
Double(
a[1],6
);
for(int i = 0;i < 3; ++i) {
for(int j = 0; j < 4; ++j)
cout << a[i][j] << ",";
cout << endl;
}
return 0;
}
6.Memcpy之二
輸入:
第一行是整數n (1<=n<=10)
第二行是 n個整數
輸出:
先原序輸出輸入資料中的n個整數
然後再輸出:
1,2,3,4,5,1,2,3,4,5,
123434567
167896789
#include <iostream>
using namespace std;
void Memcpy( void * src, void * dest, int size)
{
char * dest1 = (char *)dest;
char * src1 = (char *)src;
for (int i = size-1; i >= 0; i--)
dest1[i] = src1[i];
}
void Print(int * p,int size)
{
for(int i = 0;i < size; ++i)
cout << p[i] << ",";
cout << endl;
}
int main()
{
int a[10];
int n;
cin >> n;
for(int i = 0;i < n; ++i)
cin >> a[i];
int b[10] = {0};
Memcpy(a,b,sizeof(a));
Print(b,n);
int c[10] = {1,2,3,4,5,6,7,8,9,10};
Memcpy(c,c+5,5*sizeof(int)); //將c的前一半拷貝到後一半
Print(c,10);
char s[10] = "123456789";
Memcpy(s+2,s+4,5); //將s[2]開始的5個字元拷貝到s[4]開始的地方
cout << s << endl;
char s1[10] = "123456789";
Memcpy(s1+5,s1+1,4); //將s1[5]開始的4個字元拷貝到s1[1]開始的地方
cout << s1 << endl;
return 0;
}
7.編寫一個 MyMax函式,可以用來求任何陣列中的最大值 使得程式按要求輸出
#include <iostream>
using namespace std;
void *MyMax(void *a, unsigned int b, int n, int(*fun)(void *, void *))
{
int judge;
int *max = (int *)a;
for (int i = 1; i<n ; ++i)
{
judge = fun(max, (int *)a+i);
if (judge < 0)
max = (int *)a + i;
}
return max;
}
int Compare1(void * n1,void * n2)
{
int * p1 = (int * )n1;
int * p2 = (int * )n2;
return ((*p1)%10) - ((*p2)%10);
}
int Compare2(void * n1,void * n2)
{
int * p1 = (int * )n1;
int * p2 = (int * )n2;
return *p1 - *p2;
}
#define eps 1e-6
int Compare3(void * n1,void * n2)
{
float * p1 = (float * )n1;
float * p2 = (float * )n2;
if( * p1 - * p2 > eps)
return 1;
else if(* p2 - * p1 > eps)
return -1;
else
return 0;
}
int main()
{
int t;
int a[10];
float d[10];
cin >> t;
while(t--) {
int n;
cin >> n;
for(int i = 0;i < n; ++i)
cin >> a[i];
for(int i = 0;i < n; ++i)
cin >> d[i];
int * p = (int *) MyMax(a,sizeof(int),n,Compare1);
cout << * p << endl;
p = (int *) MyMax(a,sizeof(int),n,Compare2);
cout << * p << endl;
float * pd = (float * )MyMax(d,sizeof(float),n,Compare3);
cout << * pd << endl;
}
return 0;
}
8.指向指標的指標,程式填空使得輸出指定結果
#include <iostream>
using namespace std;
int main()
{
int x,y,z;
x = 10;
y = 20;
z = 30;
int * a[3] = { &x, &y,&z};
for(int *(*p)=a; p < a + 3; ++p)
cout<< * (*p) << endl;
return 0;
}
9.填寫記憶體交換函式 SwapMemory,使得程式輸出指定結果
#include <iostream>
using namespace std;
void SwapMemory(void * m1,void * m2, int size)
{
if (size > 5)
{
int *m11 = (int *)m1;
int *m22 = (int *)m2;
int temp;
for (int i = 0; i < 5; i++)
{
temp = *(m11 + i);
*(m11 + i) = *(m22 + i);
*(m22 + i) = temp;
}
}
else
{
char *m11 = (char *)m1;
char *m22 = (char *)m2;
char temp;
for (int i = 0; i < size; i++)
{
temp = *(m11 + i);
*(m11 + i) = *(m22 + i);
*(m22 + i) = temp;
}
}
}
void PrintIntArray(int * a,int n)
{
for(int i = 0;i < n; ++i)
cout << a[i] << ",";
cout << endl;
}
int main()
{
int a[5] = {1,2,3,4,5};
int b[5] = {10,20,30,40,50};
SwapMemory(a,b,5 * sizeof(int));
PrintIntArray(a,5);
PrintIntArray(b,5);
char s1[] = "12345";
char s2[] = "abcde";
SwapMemory(s1,s2,5);
cout << s1 << endl;
cout << s2 << endl;
return 0;
}