明解C語言中級篇練習題第二章
阿新 • • 發佈：2019-02-12
練習2-1
#include <time.h> #include <stdio.h> /*--- 等待x毫秒 ---*/ int sleep(unsigned long x) { clock_t c1 = clock(), c2; do { if ((c2 = clock()) == (clock_t)-1) /* 錯誤 */ return 0; } while (1000.0 * (c2 - c1) / CLOCKS_PER_SEC < x); return 1; } int main(void) { int i; clock_t start,end; start = clock(); for (i = 10; i > 0; i--) { /* 倒數 */ printf("\r%2d", i); printf(" 時鐘數 = %d",clock()); fflush(stdout); sleep(1000); /* 暫停1秒 */ } printf("\r\aFIRE!!"); printf(" 時鐘數 = %d", clock()); end = clock(); printf("\n程式開始執行後經過了%.1f秒。\n", (double)(end - start) / CLOCKS_PER_SEC); return 0; }
練習2-2
#include <time.h> #include <stdio.h> #include <string.h> /*--- 等待x毫秒 ---*/ int sleep(unsigned long x) { clock_t c1 = clock(), c2; do { if ((c2 = clock()) == (clock_t)-1) /* 錯誤 */ return 0; } while (1000.0 * (c2 - c1) / CLOCKS_PER_SEC < x); return 1; } //開頭逐一顯示字元 void gput(const char *s, int speed) { int i; for (i = 0; i < strlen(s); i++) { printf("\r%c",s[i]); sleep(speed); } return; } int main(void) { int a; printf("input 1 to start:"); scanf("%d",&a); sleep(500); if(a==1) gput("ABC",100); return 0; }
練習2-3
#include <time.h> #include <stdio.h> #include <string.h> /*--- 等待x毫秒 ---*/ int sleep(unsigned long x) { clock_t c1 = clock(), c2; do { if ((c2 = clock()) == (clock_t)-1) /* 錯誤 */ return 0; } while (1000.0 * (c2 - c1) / CLOCKS_PER_SEC < x); return 1; } //閃爍顯示字串 void bput(const char *s, int d,int e,int n) { while (n--) { printf("\r%s",s); sleep(d); printf("\r "); sleep(e); } return; } int main(void) { int a; printf("input 1 to start:"); scanf("%d",&a); sleep(500); if(a==1) bput("Welcome!",200,300,5); printf("\n"); return 0; }
練習2-4
#include <time.h>
#include <stdio.h>
#include <string.h>
int sleep(unsigned long x)
{
clock_t c1 = clock(), c2;
do {
if ((c2 = clock()) == (clock_t)-1) /* 錯誤 */
return 0;
} while (1000.0 * (c2 - c1) / CLOCKS_PER_SEC < x);
return 1;
}
void telop(const char *s, int direction, int speed, int n)
{
int i;
int cnt = 0; /* 第幾個字元在最前面 */
//char name[] = "BohYoh "; /* 要顯示的字串 */
int s_len = strlen(s); /* 字串name的字元數 */
if (direction == 0)
{
while (n--)
{
putchar('\r'); /* 把游標移到本行開頭 */
for (i = 0; i < s_len; i++)
{
if (cnt + i < s_len)
putchar(s[cnt + i]);
else
putchar(s[cnt + i - s_len]);
}
fflush(stdout);
sleep(speed);
if (cnt < s_len - 1)
cnt++; /* 下次從後一個字元開始顯示 */
else
cnt = 0; /* 下次從最前面的字元開始顯示 */
}
}
else if (direction == 1)
{
while (n--)
{
putchar('\r'); /* 把游標移到本行開頭 */
for (i = 0; i < s_len; i++)
{
if (cnt + i < s_len)
putchar(s[cnt + i]);
else
putchar(s[cnt + i - s_len]);
}
fflush(stdout);
sleep(speed);
if (cnt > 0)
cnt--;
else
cnt = s_len - 1; /* 下次從最前面的字元開始顯示 */
}
}
return;
}
int main(void)
{
char s[1024];
int direction;
int speed;
int repeat_count;
printf("input string:");
scanf("%s",s);
printf("input direction:");
scanf("%d",&direction);
printf("input speed,unit ms:");
scanf("%d",&speed);
printf("intput repeat count:");
scanf("%d",&repeat_count);
telop(s,direction,speed,repeat_count);
printf("\n");
return 0;
}
練習2-5
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int stage;
int a, b, c; /* 要進行加法運算的數值 */
int x; /* 已讀取的值 */
int n; /* 空白的寬度 */
clock_t start, end; /* 開始時間·結束時間 */
clock_t istart, iend;
int clock_sum = 0;
srand(time(NULL)); /* 設定隨機數的種子 */
printf("擴大視野心算訓練開始!!\n");
start = clock(); /* 開始計算 */
for (stage = 0; stage < 10; stage++)
{
a = 10 + rand() % 90; /* 生成10～99的隨機數 */
b = 10 + rand() % 90; /* 〃 */
c = 10 + rand() % 90; /* 〃 */
n = rand() % 17; /* 生成0～16的隨機數 */
printf("%d%*s+%*s%d%*s+%*s%d：", a, n, "", n, "", b, n, "", n, "", c);
do
{
istart = clock();
scanf("%d", &x);
if (x == a + b + c)
{
iend = clock();
printf("這道題用時%.1f秒\n",(double)(iend-istart)/CLOCKS_PER_SEC);
clock_sum += iend - istart;
break;
}
printf("\a回答錯誤。請重新輸入：");
} while (1);
}
end = clock(); /* 計算結束 */
printf("用時%.1f秒。\n", (double)(end - start) / CLOCKS_PER_SEC);
printf("平均每道題用時%.1f秒",(double)(clock_sum)/CLOCKS_PER_SEC);
return 0;
}
練習2-6 待做