用C语言编修已知1980年1月1日是星期二,输入任意一个日期计算出该天是星期几

#include
#include
int NOLEAP_MON[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31};
int LEAP_MON[13] = { 0,31,29,31,30,31,30,31,31,30,31,30,31};
bool isLeap(int year) {
return (year%400==0) || (year%4==0 &&year%100!=0);
}
int countDays(int year,int mon,int day)
{
int i,total = 0,j;
if (year< 1980) {
total = 0;
for(i=1979; i>year; i--) {
total += 365;
if(isLeap(i)) total ++;
}
if(isLeap(year)) {
for(i=12; i>mon; i--) total += LEAP_MON[i];
total += LEAP_MON[mon] - day +1;
} else {
for(i=12; i>mon; i--) total += NOLEAP_MON[i];
total += NOLEAP_MON[mon] - day +1;
}
total = - total;
} else {
total = 0;
for(i=1980; i