实验3
实验任务1
实验代码
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <windows.h>
#define N 80
void print_text(int line, int col, char text[]);
void print_spaces(int n);
void print_blank_lines(int n);
int main() {
int line, col, i;
char text[N] = "hi, April~";
srand(time(0));
for(i = 1;i <= 10; i++) {
line = rand() % 25;
col = rand() % 80;
print_text(line, col, text);
Sleep(1000);
}
return 0;
}
void print_spaces(int n) {
int i;
for(i = 1;i <= n; i++) {
printf(" ");
}
}
void print_blank_lines(int n) {
int i;
for(i = 1;i <= n; i++)
printf("\n");
}
void print_text(int line, int col, char text[]) {
print_blank_lines(line - 1);
print_spaces(col - 1);
printf("%s", text);
}
回答问题
这个程序实现了一个随机生成的面板，面板上随机分布着“hi，April~”
实验任务2
实验代码
#include <stdio.h>
long long fac(int n);
int main() {
int i, n;
printf("Enter n:");
scanf("%d", &n);
for(i = 1;i <= n; i++)
printf("%d! = %lld\n", i, fac(i));
return 0;
}
long long fac(int n) {
static long long p = 1;
p = p * n;
return p;
}
#include <stdio.h>
int func(int, int );
int main() {
int k = 4, m = 1, p1, p2;
p1 = func(k, m);
p2 = func(k, m);
printf("%d, %d\n", p1, p2);
return 0;
}
int func(int a, int b) {
static int m = 0, i = 2;
i += m + 1;
m = i + a + b;
return m;
}
实验结论
回答问题
static变量能使变量在每次函数调用中保持刚刚的值不变
实验任务3
实验代码
#include <stdio.h>
long long func(int n);
int main() {
int n;
long long f;
while(scanf("%d", &n) != EOF) {
f = func(n);
printf("n = %d, f = %lld\n", n, f);
}
return 0;
}
long long func(int n) {
long long sum = 1;
for(int i = 1;i <= n; i++)
sum *= 2;
return sum - 1;
}
实验结论
实验任务4
实验代码
#include <stdio.h>
int func(int n, int m);
int main() {
int n, m;
while(scanf("%d%d", &n, &m) != EOF)
printf("n = %d, m = %d, ans = %d\n", n, m, func(n, m));
return 0;
}
int func(int n, int m) {
if(n < m) return 0;
else if(n == 0 || m == 0 ||n == m) return 1;
else return func(n - 1, m) + func(n - 1, m - 1);
}
实验结论
实验任务5
实验代码
#include <stdio.h>
double mypow(int x, int y);
int main() {
int x, y;
double ans;
while(scanf("%d %d", &x, &y) != EOF) {
ans = mypow(x, y);
printf("%d的%d次方：%g\n\n", x, y, ans);
}
return 0;
}
double mypow(int x, int y) {
int t, i;
if(y < 0) t = -y;
else t = y;
double sum = 1;
for(i = 1;i <= t; i++)
sum *= x;
if(y > 0) return sum;
else return 1.0 / sum;
}
#include <stdio.h>
double mypow(int x, int y);
int main() {
int x, y;
double ans;
while(scanf("%d %d", &x, &y) != EOF) {
ans = mypow(x, y);
printf("%d的%d次方：%g\n\n", x, y, ans);
}
return 0;
}
double mypow(int x, int y) {
if(y == 0) return 1;
if(y > 0) return x * mypow(x, y - 1);
if(y < 0) return 1.0 / x * mypow(x, y + 1);
}
实验结论
实验任务6
实验代码
#include <stdio.h>
#include <stdlib.h>
void hanoi(unsigned int n, char from, char temp, char to);
void moveplate(unsigned int n, char from, char to);
int tot;
int main() {
unsigned int n;
while(scanf("%u", &n) != EOF) {
tot = 0;
hanoi(n, 'A', 'B', 'C');
printf("一共移动了%d次\n", tot);
}
system("pause");
return 0;
}
void hanoi(unsigned int n, char from, char temp, char to) {
if(n == 1)
moveplate(n, from, to);
else {
hanoi(n - 1, from, to, temp);
moveplate(n, from, to);
hanoi(n - 1, temp, from, to);
}
}
void moveplate(unsigned int n, char from, char to) {
tot ++;
printf("%u: %c --> %c\n", n, from, to);
}
实验结论
实验任务7
实验代码
#include <stdio.h>
int is_prime(int x);
int main() {
int i, n;
while(scanf("%d", &n) != EOF) {
for(i = 2;i <= n; i++) {
if(!is_prime(i) || !is_prime(n - i)) continue ;
printf("%d = %d + %d\n", n, i, n - i);
break ;
}
}
return 0;
}
int is_prime(int x) {
int i;
for(i = 2;i * i <= x; i++)
if(x % i == 0) return 0;
return 1;
}
实验结论
实验代码
#include <stdio.h>
#include <math.h>
long func(long s);
int main() {
long s, t;
printf("Enter a number: ");
while(scanf("%ld", &s) != EOF) {
t = func(s);
printf("new number is：%ld\n\n", t);
printf("Enter a number: ");
}
return 0;
}
long func(long s) {
long t = 0, t1 = 0;
while(s > 0) {
int tmp = s % 10;
s /= 10;
if(tmp % 2 == 1) t1 = t1 * 10 + tmp;
}
while(t1 > 0) {
t = t * 10 + (t1 % 10);
t1 /= 10;
}
return t;
}
实验结论
