两个日期相差天数（不知道哪错了，能不能帮我看看）

Question

#include<stdio.h>

int main()
{int y1,m1,d1,y2,m2,d2,a=0,b,t,f1=0,f2=0,f3=0;
scanf("%d-%d-%d %d-%d-%d",&y1,&m1,&d1,&y2,&m2,&d2);
if(y2-y1==1)f3=1;
if((y1%4==0&&y1%100!=0)||y1%400==0)
f1=1;
for(;y1<y2;y1++){
if((y1%4==0&&y1%100!=0)||y1%400==0){
a+=366;
}else a+=365;
}
if((y1%4==0&&y1%100!=0)||y1%400==0)
f2=1;
if(m1>m2){
t=m1;
m1=m2;
m2=t;
b=-1;
}else b=1;
for(;m1<m2;m1++){
switch(m1){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:a+=31b;
break;
case 4:
case 6:
case 9:
case 11:a+=30b;
break;
case 2:if(f2==1){
a+=29b;
}else a+=28b;
break;
}
}
a+=d2-d1;
if(f1==1&&f2==0&&f3==1)a-=1;
if(f1==0&&f2==1&&f3==1)a+=1;

printf("%d",a);
return 0;

}

Answer 1

#include<stdio.h>

int main()
{int y1,m1,d1,y2,m2,d2,a=0,s,i,s1,s2;
scanf("%d-%d-%d %d-%d-%d",&y1,&m1,&d1,&y2,&m2,&d2);
int n=y1;
for(;y1<y2;y1++){
if((y1%4==0&&y1%100!=0)||y1%400==0){
a+=366;
}else a+=365;
}
for(i=1,s=0;i<m1;i++){
switch(i){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:s+=31;
break;
case 4:
case 6:
case 9:
case 11:s+=30;
break;
case 2:if((n%4==0&&n%100!=0)||n%400==0){
s+=29;
}else s+=28;
break;
}
}
s1=s+d1;
for(i=1,s=0;i<m2;i++){
switch(i){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:s+=31;
break;
case 4:
case 6:
case 9:
case 11:s+=30;
break;
case 2:if((y2%4==0&&y2%100!=0)||y2%400==0){
s+=29;
}else s+=28;
break;
}
}
s2=s+d2;
a+=s2-s1;
printf("%d",a);
return 0;
}