C 练习实例4
题目:输入某年某月某日,判断这一天是这一年的第几天?
程序分析:以3月5日为例,应该先把前两个月的加起来,然后再加上5天即本年的第几天,特殊情况,闰年且输入月份大于3时需考虑多加一天。
实例
#include <stdio.h>
int main()
{
int day,month,year,sum,leap;
printf("\n请输入年、月、日,格式为:年,月,日(2015,12,10)\n");
scanf("%d,%d,%d",&year,&month,&day); // 格式为:2015,12,10
switch(month) // 先计算某月以前月份的总天数
{
case 1:sum=0;break;
case 2:sum=31;break;
case 3:sum=59;break;
case 4:sum=90;break;
case 5:sum=120;break;
case 6:sum=151;break;
case 7:sum=181;break;
case 8:sum=212;break;
case 9:sum=243;break;
case 10:sum=273;break;
case 11:sum=304;break;
case 12:sum=334;break;
default:printf("data error");break;
}
sum=sum+day; // 再加上某天的天数
if(year%400==0||(year%4==0&&year%100!=0)) {// 判断是不是闰年
leap=1;
} else {
leap=0;
}
if(leap==1&&month>2) { // *如果是闰年且月份大于2,总天数应该加一天
sum++;
}
printf("这是这一年的第 %d 天。",sum);
printf("\n");
}
以上实例输出结果为:
请输入年、月、日,格式为:年,月,日(2015,12,10) 2015,10,1 这是这一年的第 274 天。

文人墨客
参考方法:
#include<stdio.h> //某月的天数 int getMonthDay(int month) { int day = 0; switch(month){ case 2: day = 28; break; case 1: case 3: case 5: case 7: case 8: case 10: case 12: day = 31; break; case 4: case 6: case 9: case 11: day = 30; break; } return day; } //是否闰年 int isleap(int year) { if ( (year%4==0 && year%100!=0) || (year%400==0) ){ return 1; } return 0; } int main() { int year, month, day; printf("请输入年月日(2019-5-1):\n"); scanf("%d-%d-%d", &year, &month, &day); int days = day, m; for(m=1; m<month; m++){ days += getMonthDay(m); } if (isleap(year)==1){ days += 1; } printf("%d-%d-%d是这一年的第%d天", year, month, day, days); return 0; }文人墨客
参考方法:
#include<stdio.h> int IsLeap(int year) { if((year%4==0&&year%100!=0)||(year%400==0)) return 1; else return 0; } int main(void) { int monthday[2][13] = {{0,31,28,31,30,31,30,31,31,30,31,30,31}, {0,31,29,31,30,31,30,31,31,30,31,30,31}}; int year,month,day; int sum = 0; printf("请输入年、月、日,格式为:年,月,日(2015,12,10)\n"); scanf("%d,%d,%d",&year,&month,&day); if(IsLeap(year)) { for(int i = 0; i < month; i++) { sum += monthday[1][i]; } } else { for(int i = 0; i < month; i++) { sum += monthday[0][i]; } } sum += day; printf("这是这一年的第 %d 天。",sum); return 0; }文人墨客
参考方法:
#include <stdio.h> int main(){ int year,month,day; // 一、 二、 三、 四、 五、六 、七、八、九、十、十一、十二 int monthOfDayNumber[] = {31, 28, 31, 30, 31, 30,31,31,30,31,30,31}; printf("\n请输入年、月、日,格式为:年,月,日(2015,12,10)\n"); scanf("%d,%d,%d",&year,&month,&day); // 格式为:2015,12,10 int sum=0,leap=0; if(year%400==0||(year%4==0&&year%100!=0)){ leap = 1; } if(month>=3){ printf("闰年: %d\n",leap); sum = sum + leap; } for(;month-2>=0;month--){ sum += monthOfDayNumber[month-2]; } sum += day; printf("此日期是%d年的第%d天\n",year,sum); return 0; }文人墨客
参考方法:
#include <stdlib.h> #include <stdio.h> int main(void) { int year,month,day,a=0; printf("\n请输入年、月、日,格式为:年 月日(2015 12 10)\n"); scanf("%d%d%d",&year,&month,&day); int alldays=0; if((year%4==0 && year%100!=0) || year%400==0) a=1; switch(month-1) { case 11:alldays=alldays+30; case 10:alldays=alldays+31; case 9:alldays=alldays+30; case 8:alldays=alldays+31; case 7:alldays=alldays+31; case 6:alldays=alldays+30; case 5:alldays=alldays+31; case 4:alldays=alldays+30; case 3:alldays=alldays+31; case 2:alldays=alldays+(28+a); case 1:alldays=alldays+31; } alldays=alldays+day; printf("year:%d\nmonth:%d\nday:%d\nalldays:%d\n",year,month,day,alldays); }文人墨客
参考方法:
#include<stdio.h> int main() { printf("请输入日期(格式:xxxx.xx.xx):"); int year,month,date; scanf("%d.%d.%d",&year,&month,&date); int md[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};/*多写一个,方便标号*/ /*判断是否是闰年*/ if(((year%4==0)&&(year%100!=0))||(year%400==0)) { md[2]+=1; } /*判断日期符合实际*/ if(year<=0||month<1||month>12||date<1||date>md[month]) { printf("输入数据无效!\n"); return 0; } int mi,days=0; for (mi=0;mi<month;mi++) { days+=md[mi]; } printf("%d.%d.%d是这一年的第%d天。\n",year,month,date,days+date); return 0; }文人墨客
参考方法:
#include<stdio.h> int main() { int year, month, day,sumday=0; int monthday[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; printf("请输入年、月、日,格式为:年,月,日(2015,12,10)\n"); scanf("%d,%d,%d",&year,&month,&day); if (year % 400 == 0 || (year % 100 != 0 && year % 4 == 0)) { monthday[1] =29; } for (int i = 0; i < month-1; i++) { sumday += monthday[i]; } sumday += day; printf("%d\n",sumday); return 0; }