请教 哪里错了
#include <stdio.h> int main() { /* 定义需要计算的日期 */ int year = 2008; int month = 8; int day = 8; int i =1; int num=0; if( ; i<month; i++) { switch(i) { case 1 : num= num +31; break; case 2: nun = num +29; break; case 3: num=num+31 ; break; case 4 : num = num +30; break; case 5: num = num+31; break; case 6 : num = num+30; break; case 7 : num = num +31 ; break; } num = num ; } else { printf("%dnum="num+day); } return 0; }