/*今天是2013 年4 月4 日星期四,编写程序,输入今天开始到12 月31 日之间的任 意日期,输出那一天是星期几。*/ #include <stdio.h> int main(){ int today_m,today_d,today_w; int month, day, result; int i,j,k,sum; int list[] = {0,31,28,31,30,31,30,31,31,30,31,30,31}; today_m = 4; today_d = 4; today_w = 4; printf("Please input month,day:\n"); do{ scanf("%d,%d",&month,&day); if((month >0 && month <= 12) && day <= list[month]) break; else printf("error input !\n"); }while(1); sum = 0; if(month >= 4){ for(i = today_m; i < month; i++) sum += list[i]; sum = sum + day - today_d; result = (sum + today_w) % 7; } else if(month < 4){ for(i = month; i < today_m; i++) sum +=list[i]; sum = sum + today_d - day; result = (sum - today_w) % 7; } switch(result){ case 0: printf("sunday\n"); break; case 1: printf("monday\n"); break; case 2: printf("tuseday\n"); break; case 3: printf("Wednesday\n"); break; case 4: printf("Thursday\n"); break; case 5: printf("Friday\n"); break; case 6: printf("Saturday\n"); break; default: break; } }