int main() { printf("请输入月份:"); int month; scanf("%d",&month); switch(month) { case 1: printf("January\n"); break; case 2: printf("February\n"); break; case 3: printf("March\n"); break; case 4: printf("April\n"); break; case 5: printf("May\n"); break; case 6: printf("June\n"); break; case 7: printf("July\n"); break; case 8: printf("August\n"); break; case 9: printf("September\n"); break; case 10: printf("0ctobern"); break; case 11: printf("Novembern"); break; case 12: printf("December\n"); break; default: printf("错误\n"); break; } return 0; }

# include <stdio.h> int main() { int score,mark; char grade; printf("please input score:"); scanf("%d",&score); mark=score/10; switch(mark) { case 0: case 1: case 2: case 3: case 4: case 5: printf("grade:E\n"); break; case 6: printf("grade:E\n"); break; case 7: printf("grade:E\n"); break; case 8: printf("grade:E\n"); break; case 9: printf("grade:E\n"); break; case 10: printf("grade:E\n"); break; default: printf("input error!\n"); } return 0; }

# include <stdio.h> int main() { int score,mark; char grade; printf("please input score:"); scanf("%d",&score); mark=score>=0&&score<=100?score/10:-1; switch(mark) { case 0: case 1: case 2: case 3: case 4: case 5: printf("grade:E\n"); break; case 6: printf("grade:E\n"); break; case 7: printf("grade:E\n"); break; case 8: printf("grade:E\n"); break; case 9: printf("grade:E\n"); break; case 10: printf("grade:E\n"); break; default: printf("input error!\n"); } return 0; }

int main() { int data1, data2; char op; printf("please enter the expression:"); scanf("%d %c%d", &data1, &op, &data2); switch (op) { case '+' : printf("%d + %d = %d\n", data1, data2, data1 + data2); break; case '-' : printf("%d - %d = %d\n", data1, data2, data1 - data2); break; case '*' : printf("%d * %d = %d\n", data1, data2, data1 * data2); break; case '/' : if (0 == data2) printf("Division by zero!\n"); else printf("%d / %d = %d\n", data1, data2, data1 / data2); break; default : printf("Unknown operator!\n"); } return 0; }

int main( ) { int year, month, data, days = 0; printf("Please input year-month-date:"); scanf("%d-%d-%d", &year, &month, &data); switch (month) { case 12: days += 30; /*将11月份的天数加进来*/ case 11: days += 31; /*将10月份的天数加进来*/ case 10: days += 30; /*将9月份的天数加进来*/ case 9: days += 31; /*将8月份的天数加进来*/ case 8: days += 31; /*将7月份的天数加进来*/ case 7: days += 30; case 6: days += 31; case 5: days += 30; case 4: days += 31; case 3: days += ((year%4==0 && year%100!=0 || year%400==0) ? 29 : 28); /*将2月份的天数加进来*/ case 2: days += 31; /*将1月份的天数加进来*/ } days += data; printf("It's the %d day of the year.\n", days); return 0; }

int main(void) { int score, mark; printf("Please input score:"); scanf("%d", &score); mark = score>=0&&score<=100 ? score/10 : -1; switch (mark) { case 0: case 1: case 2: case 3: case 4: case 5: printf("garde:E\n"); break; case 6: printf("garde:D\n"); break; case 7: printf("garde:C\n"); break; case 8: printf("garde:B\n"); break; case 9: case 10: printf("garde:A\n"); break; default: printf("error!\n"); } return 0; }

#include <stdio.h> int main(void) { float a, b, c; printf("Input the three edge length:"); scanf("%f, %f, %f", &a, &b , &c); if (a+b>c && b+c>a && a+c>b) { if (a==b || b==c || c==a) printf("等腰三角形\n"); else if (a*a+b*b==c*c || a*a+c*c==b*b || b*b+c*c==a*a) printf("直角三角形\n"); else printf("一般三角形\n"); } else { printf("不是三角形\n"); } return 0; }

#include <stdio.h> int main(void) { float a, b, c; printf("Input the three edge length:"); scanf("%f, %f, %f", &a, &b , &c); if (a+b>c && b+c>a && a+c>b) { if (a==b || b==c || c==a) printf("等腰三角形\n"); if (a*a+b*b==c*c || a*a+c*c==b*b || b*b+c*c==a*a) printf("直角三角形\n"); else printf("一般三角形\n"); } else { printf("不是三角形\n"); } return 0; }

#include <stdio.h> #include <math.h> int main(void) { float a, b, c; printf("Input the three edge length:"); scanf("%f, %f, %f", &a, &b , &c); if (a+b>c && b+c>a && a+c>b) { if (fabs(a-b)<=0.1||fabs(b-c)<=0.1||fabs(c-a)<=0.1) printf("等腰三角形\n"); if (fabs(a*a+b*b-c*c)<=0.1 || fabs(a*a+c*c-b*b)<=0.1 || fabs(b*b+c*c-a*a)<=0.1) printf("直角三角形\n"); else printf("一般三角形\n"); } else { printf("不是三角形\n"); } return 0; }

#include <stdio.h> #include <math.h> int main(void) { float a, b, c; printf("Input the three edge length:"); scanf("%f, %f, %f", &a, &b , &c); if (a+b>c && b+c>a && a+c>b) { if (fabs(a-b)<=0.1||fabs(b-c)<=0.1||fabs(c-a)<=0.1) printf("等腰"); if (fabs(a*a+b*b-c*c)<=0.1 || fabs(a*a+c*c-b*b)<=0.1 || fabs(b*b+c*c-a*a)<=0.1) printf("直角"); else printf("一般"); printf("三角形\n"); } else { printf("不是三角形\n"); } return 0; }