Project Euler：Problem 19 Counting Sundays

You are given the following information, but you may prefer to do some research for yourself.

• 1 Jan 1900 was a Monday.
• Thirty days has September,
  April, June and November.
  All the rest have thirty-one,
  Saving February alone,
  Which has twenty-eight, rain or shine.
  And on leap years, twenty-nine.
• A leap year occurs on any year evenly divisible by 4, but not on a century unless it is divisible by 400.

How many Sundays fell on the first of the month during the twentieth century (1 Jan 1901 to 31 Dec 2000)?

题意就是计算从1901年1月1号到2000年12月31号中第一天为星期天的月份数为多少。

好吧开始我又看错题目了，高高兴兴求这100年有多少个星期天提交结果不对才发现(╯‵□′)╯︵┻━┻我脑子里面在想什么

#include <iostream>using namespace std;bool leap(int a){if ((a % 4 == 0 && a % 100 != 0) || (a % 400 == 0))return true;return false;}int main(){int a[2][12] = { { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } };int day = 367;int count = 0;for (int i = 1901; i <= 2000; i++){int t = 0;if (leap(i))t = 1;for (int j = 0; j < 12; j++){day += a[t][j];if (day % 7 == 0)count++;}}cout << count << endl;system("pause");return 0;}