C语言_日期_周计算

小灰灰 2022-12-04 07:57 212阅读 0赞

# 日期计算 #

## 计算指定日期是周几 ##

#include <stdio.h>
    #include <stdlib.h>
    
    int Day(int y, int m, int d);
    
    int main(int argc, char *argv[])
    { 
        int year, month, day; //读取用户输入的年月日
        int days;             //储存从1900-1-1到该天的天数
        int week = 0;         //储存求余后的星期
            //字符串组合输出星期
        char b[] = { "星期"};
        char c[7][4] = { "日", "一", "二", "三", "四", "五", "六"};
    
    loop:
        printf("请输入年 月 日：（空格分隔）\n");
        scanf("%d%d%d", &year, &month, &day);
        days = Day(year, month, day);
        //增强程序的健壮性
        if (days == -1)
        { 
            printf("输入格式有误，");
            fflush(stdin); //防止用户输入字母等其他非数字字符
            goto loop;
        }
        else
        { 
            week = days % 7; //用求余计算星期几
            printf("%d年%d月%d日是%s%s\n", year, month, day, b, c[week]);
        }
        system("pause");
        return 0;
    }
    
    //函数功能：输入年月日，输出1900-1-1到该天的天数，-1位输入不合法
    int Day(int y, int m, int d)
    { 
        int i;
        int r = 0;                                              //储存1900到该天的闰年个数
        int a[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30}; //m给出每月的天数
    
        if (y >= 1900 && m > 0 && m < 13 && d > 0 && d < 32)
        { 
            for (i = 1900; i <= y; i++) //计算闰年的个数
            { 
                if (i % 400 == 0 || i % 100 != 0 && i % 4 == 0)
                    r++;
            }
            for (i = 0; i < m - 1; i++) //统计当年1月1日到当月的天数
            { 
                d += a[i];
            }
            if ((y % 400 == 0 || y % 100 != 0 && y % 4 == 0) && m < 3) //如果当年是闰年但不到二月就不能算进去
                r--;
            return 365 * (y - 1900) + r + d;
        }
        else
            return -1;
    }

参考百度知道

## 输出日历数组 ##

#include <stdio.h>
    
    #define IS_LEAP_YEAR(y) ((((y) % 4 == 0) && ((y) % 100 != 0)) || ((y) % 400 == 0))
    
    //if( ((0 == year%4)&&(0 != year%100)) ||(0 == year %400) )
    //2018
    int Leap_year[] = { 
    	31, 29, 31,
    	30, 31, 30,
    	31, 31, 30,
    	31, 30, 31};
    int No_Leap_year[] = { 
    	31, 28, 31,
    	30, 31, 30,
    	31, 31, 30,
    	31, 30, 31};
    
    int PrintfDate(int year, int i16DayOffset, FILE* fp)
    { 
    	//int i16DayOffset = 0;
    	int i16Month = 0;
    	int i16Week = 0;
    	int i16DayCnt = 0;
    	int i16DisplayDay = 0;
    	int i16RunOneTime = 1;
    	int i16NA = 0;
    
    	if (year == 2018)
    	{ 
    		i16DayOffset = 1;
    	}
    
    	i16DayCnt = i16DayOffset;
    
    	//月 周 日历
    	fprintf(fp, "Date%d[53][9]={\n", year);
    
    	if (IS_LEAP_YEAR(year))
    	{ 
    		//printf("Leap_year\n");
    		for (i16Month = 0; i16Month <= 11; i16Month++)
    		{ 
    			for (i16DisplayDay = 1; i16DisplayDay <= No_Leap_year[i16Month]; i16DisplayDay++)
    			{ 
    				if ((i16RunOneTime) && (0 != i16DayOffset))
    				{ 
    					i16Week = 1;
    					fprintf(fp, "%4d,", i16Month + 1);
    					fprintf(fp, "%4d,", i16Week);
    					i16RunOneTime = 0;
    				}
    
    				while (i16DayOffset)
    				{ 
    					//printf(" ");
    					fprintf(fp, "%4d,", i16NA);
    					//printf("%4s,",' ');
    					i16DayOffset = i16DayOffset - 1;
    				}
    
    				if (i16DayCnt % 7 == 0)
    				{ 
    					i16Week++;
    					fprintf(fp, "\n");
    					fprintf(fp, "%4d,", i16Month + 1);
    					fprintf(fp, "%4d,", i16Week);
    				}
    				else
    				{ 
    				}
    				//printf("%4d",i16DayCnt);
    				fprintf(fp, "%4d,", i16DisplayDay);
    				i16DayCnt++;
    			}
    		}
    	}
    	else
    	{ 
    		//printf("No_Leap_year\n");
    		for (i16Month = 0; i16Month <= 11; i16Month++)
    		{ 
    			for (i16DisplayDay = 1; i16DisplayDay <= No_Leap_year[i16Month]; i16DisplayDay++)
    			{ 
    				if ((i16RunOneTime) && (0 != i16DayOffset))
    				{ 
    					i16Week = 1;
    					fprintf(fp, "%4d,", i16Month + 1);
    					fprintf(fp, "%4d,", i16Week);
    					i16RunOneTime = 0;
    				}
    
    				while (i16DayOffset)
    				{ 
    					//printf(" ");
    					//printf("%4s,",' ');
    					fprintf(fp, "%4d,", i16NA);
    					i16DayOffset = i16DayOffset - 1;
    				}
    
    				if (i16DayCnt % 7 == 0)
    				{ 
    					i16Week++;
    					fprintf(fp, "\n");
    					fprintf(fp, "%4d,", i16Month + 1);
    					fprintf(fp, "%4d,", i16Week);
    				}
    				else
    				{ 
    				}
    				//printf("%4d",i16DayCnt);
    				fprintf(fp, "%4d,", i16DisplayDay);
    				i16DayCnt++;
    			}
    		}
    	}
    	fprintf(fp, "\n");
    	fprintf(fp, "};\n");
    
    	i16DayOffset = i16DayCnt % 7;
    
    	//printf("\n");
    	//printf("DayOffset %4d",i16DayOffset);
    	//printf("\n");
    	
    	return i16DayOffset;
    }
    
    int main()
    { 
    	FILE *fp = NULL;
    	fp = fopen("./date.c", "wb");
    	if (NULL == fp)
    	{ 
    		printf("Failed to create 'data.c'\n");
    		return -1;
    	}
    	
    	int i16DayOffset = 0;
    
    	i16DayOffset = PrintfDate(2018, 1, fp); //init Offset
    	for (int year = 2019; year < 2050; year++)
    	{ 
    		i16DayOffset = PrintfDate(year, i16DayOffset, fp);
    	}
    	
    	fclose(fp);
    	fp = NULL;
    	return 0;
    }