switch case 选择
- 假设用1,2。。。。7分别表示星期一。。。。星期天,现输入一个数字,输出对应的星期几。比如:输入3,则输出“星期三”
#define _CRT_SECURE_NO_WARNINGS 1 #include <stdio.h> int main() {int day = 0;scanf("%d", &day);switch (day){case 1:printf("星期一\n");break;case 2:printf("星期二\n");break;case 3:printf("星期三\n");break;case 4:printf("星期四\n");break;case 5:printf("星期五\n");break;case 6:printf("星期六\n");break;case 7:printf("星期天\n");break;}return 0; }
从键盘上输入学生成绩,成绩等级如下:60分及其以上为通过,60分以下为不通过#define _CRT_SECURE_NO_WARNINGS 1 #include <stdio.h> int main() {int d = 0;scanf("%d", &d);int n;n = d > 60 ? 0 : 1;switch (n){case 0:printf("合格\n");break;case 1:printf("不合格\n");break;}return 0; }
- 从键盘上输入学生成绩,成绩等级如下:
90~100 “优”
80~90 “良”
70~80 “中”
60~70 “合格”
60以下 “不合格”#define _CRT_SECURE_NO_WARNINGS 1 #include <stdio.h> int main() {int d = 0;scanf("%d", &d);int n;n = d > 60 ? 1: 0;if (n){d /= 10;switch (d){case 6:printf("合格\n");break;case 7:printf("中\n");break;case 8:printf("良\n");break;case 9:printf("优\n");break;case 10:printf("优\n");break;}}elseprintf("不合格");return 0; }
while循环
- 求1到10之间奇数的和与偶数的和
#define _CRT_SECURE_NO_WARNINGS 1 #include <stdio.h> int main() {int a = 0, b = 0, c = 1, d;printf("请输入一个数字求 1~这个数字 范围内的偶数和奇数的和\n");scanf("%d", &d);while (c <= d){if (c % 2 == 0)a = a + c;elseb = b + c;c++;}printf("偶数和是 %d,奇数和是 %d\n", a, b);return 0; }
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求1/2+1/4+1/6+……的和,最后一项的值小于0.0001为止。
#define _CRT_SECURE_NO_WARNINGS 1 #include <stdio.h> int main() {int a = 2;double sum = 0;while (a <= 10002){sum = sum + 1.0 / a;a += 2;}printf("%lf\n", sum);return 0; }
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求和1/2-1/3+1/4-1/5+1/6……+1/100
#define _CRT_SECURE_NO_WARNINGS 1 #include <stdio.h> int main() {double b = 1.0, sum = 0, a;int i = 1;while(i <= 100){a = b / i;sum += a;b = -b;i++;}printf("sum = %.2f\n", sum);return 0; }
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、求10!(求10的阶乘)
#define _CRT_SECURE_NO_WARNINGS 1 #include <stdio.h> int main() { int p = 1;int n;int i = 2;printf("请输入所求阶乘数:\n");scanf("%d", &n);while(i <= n) {p = p * i;++i;}printf("%d! = %d", n, p);return 0; }