c++格式输出某年某月的日历

#include
#include
#include 
#include 
#include
 using namespace std;
int mmday(int yy,int mm){//返回该年月份的天数
    switch(mm){
        case 1: case 3: case 5: case 7: case 8: case 10: case 12:
                
                return 31;
                
                break;
        case 4: case 6: case 9: case 11:
                
               return 30;
                
                break;
            case 2:
                if ((yy % 4 == 0 && yy % 100 != 0) || (yy % 400 == 0))
                { return 29; }
                else { return 28; }
                break;
        default: return 0 ;
    }
}
int countweek(int yy,int mm,int dd){
    if (yy < 1900 || yy>2100) {
        cout << "输入的日期不正确"; return -1;}
    else {
        int day_org = 0;
        int day_pass=dd;
        
        day_org=((yy-1)*365+(yy-1)/4-(yy-1)/100+(yy-1)/400)%7 ;
        
        for (int j = 1; j < mm; j++)
            
        {
            
            switch (j){ case 1: case 3: case 5: case 7: case 8: case 10: case 12:
                    
                    day_pass += 31;
                    
                    break; case 4: case 6: case 9: case 11:
                    
                    day_pass+= 30;
                    
                    break;
                case 2:
                    if ((yy % 4 == 0 && yy % 100 != 0) || (yy % 400 == 0))
                    { day_pass += 29; }
                    else { day_pass += 28; }
                    break;
                default: cout << "error" << endl; break; }
        }
        return (day_pass + day_org) % 7; //0代表周日
    }
    
}

int main(){
     
    int mm,yy,dd,day=1,row=1,col=1;//6行7列
    cin>>yy>>mm;
    dd=mmday(yy,mm);//总天数
    cout<
       
        if(i==0)//对第一行的操作
        {
            for(int k=0;kcout<
                for(int j=0;j<7;j++)//对其他5行的处理
                 {   if(day>31)
                        {break;}
                    countweek(yy,mm,day);
                     cout<