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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. int days_in_month (int y, int m) {
  5.   // Fourth, eleventh, ninth, and sixth,
  6.   // thirty days to each we fix. 
  7.   if ((m==4)||(m==11)||(m==9)||(m==6)) return 30; 
  8.   // Every other, thirty-one,
  9.   // except the second month alone,
  10.   if (m!=2) return 31;
  11.   // which hath twenty-eight, in fine,
  12.   // till leap-year give it twenty-nine.
  13.   if ((y%400)==0) return 29; // leap year
  14.   if ((y%100)==0) return 28; // not a leap year
  15.   if ((y%4)==0)   return 29; // leap year
  16.   return 28; // not a leap year 
  17. }
  18.  
  19. int ymdToWeekNumberA (int y, int m, int d) {
  20.   // reject out-of-range input
  21.   if ((y < 1583)||(y > 25000)) return 0;
  22.   if ((m < 1)||(m > 12)) return 0;
  23.   if ((d < 1)||(d > 31)) return 0;
  24.   // compute correction for year
  25.   //     If Jan. 1 falls on: Mo Tu We Th Fr Sa Su
  26.   // then the correction is:  0 +1 +2 +3 -3 -2 -1
  27.   int corr = ((y + 2 + (y-1)/4 - (y-1)/100 + (y-1)/400) % 7) - 3;
  28.   // compute day of the year (in range 1-366)
  29.   int doy = d;
  30.   if (m > 1) doy += 31;
  31.   if (m > 2) doy += (((y%100) ? (y%4) : (y%400)) ? 28 : 29);
  32.   if (m > 3) doy += 31;
  33.   if (m > 4) doy += 30;
  34.   if (m > 5) doy += 31;
  35.   if (m > 6) doy += 30;
  36.   if (m > 7) doy += 31;
  37.   if (m > 8) doy += 31;
  38.   if (m > 9) doy += 30;
  39.   if (m > 10) doy += 31;
  40.   if (m > 11) doy += 30;
  41.   // compute corrected day number
  42.   int cdn = corr + doy;
  43.   // compute number of weeks, rounding up to nearest whole week
  44.   // this gives us our week number
  45.   int wknum = ((cdn + 6) / 7);
  46.   // check for boundary conditions:
  47.   // if our calculation would give us "week 0",
  48.   // then it is really the final week of the previous year
  49.   // and we need to find out whether that is week 52 or week 53
  50.   if (wknum < 1) {
  51.     // first, compute correction for the previous year
  52.     corr = ((y + 1 + (y-2)/4 - (y-2)/100 + (y-2)/400) % 7) - 3;
  53.     // then, compute day of year with respect to that same previous year
  54.     doy = d + ((((y-1)%100) ? ((y-1)%4) : ((y-1)%400)) ? 365 : 366);
  55.     // finally, re-compute the corrected day number and the week number
  56.     cdn = corr + doy;
  57.     wknum = ((cdn + 6) / 7);
  58.     return wknum;
  59.   }
  60.   // if our calculation would give us "week 53",
  61.   // we need to find out whether week 53 really exists,
  62.   // or whether it is week 1 of the following year
  63.   if (wknum > 52) {
  64.     // check for year beginning on Thurs.
  65.     if (corr==3) return 53;
  66.     // check for leap year beginning on Wed.
  67.     if ((((y%100)?(y%4):(y%400))==0) && (corr==2)) return 53;
  68.     // otherwise, there is no week 53
  69.     return 1;
  70.   }
  71.   return wknum;
  72. }
  73.  
  74. int ymdToWeekNumberB (int y, int m, int d) {
  75.   if ((y < 1583)||(y > 25000)) return 0;
  76.   if ((m < 1)||(m > 12)) return 0;
  77.   if ((d < 1)||(d > 31)) return 0;
  78.   int adj = ((y + 2 + (y-1)/4 - (y-1)/100 + (y-1)/400) % 7) + 3;
  79.   int doy = d;
  80.   for (int i=1; i<m; i++) doy += (30 + ((0x15AA >> i) & 1));
  81.   if (m > 2) doy -= (((y%100) ? (y%4) : (y%400)) ? 2 : 1);
  82.   int wknum = (adj + doy) / 7;
  83.   if (wknum < 1) {
  84.     adj = ((y + 1 + (y-2)/4 - (y-2)/100 + (y-2)/400) % 7) + 3;
  85.     if (adj==9) return 53;
  86.     if ((adj==8) && ((((y-1)%100)?(y%4):(y%400))==1)) return 53;
  87.     return 52;
  88.   }
  89.   if (wknum > 52) {
  90.     if (adj==9) return 53;
  91.     if ((adj==8) && (((y%100)?(y%4):(y%400))==0)) return 53;
  92.     return 1;
  93.   }
  94.   return wknum;
  95. }
  96.  
  97. int main() {
  98. 	int yyyy=1583, mo=1, dd=3, wd=1, wn=1;
  99. 	int wna, wnb;
  100. 	int errcnta=0, errcntb=0;
  101. 	while (yyyy<=25000) {
  102. 		wna=ymdToWeekNumberA(yyyy,mo,dd);
  103. 		wnb=ymdToWeekNumberB(yyyy,mo,dd);
  104. 		if ((wn!=wna)||(wn!=wnb)) {
  105. 			if ((errcnta<100)&&(errcntb<100)) {
  106. 				cout << yyyy << "/" << mo << "/" << dd << "  ";
  107. 				cout << "W" << wn << "-" << wd << "  ";
  108. 				cout << "A=" << wna << "  B=" << wnb << "\n";
  109. 			}
  110. 			if (wn!=wna) errcnta++;
  111. 			if (wn!=wnb) errcntb++;
  112. 		}
  113. 		dd++;
  114. 		if (dd>days_in_month(yyyy,mo)) {
  115. 			dd=1;
  116. 			mo++;
  117. 			if (mo>12) {
  118. 				mo=1;
  119. 				yyyy++;
  120. 			}
  121. 		}
  122. 		wd++;
  123. 		if (wd>7) {
  124. 			wd=1;
  125. 			wn++;
  126. 			if (((mo==12)&&(dd>=29))||((mo==1)&&(dd<=4))) wn=1;
  127. 		}
  128. 	}
  129. 	cout << "Errors (A): " << errcnta << "\n";
  130. 	cout << "Errors (B): " << errcntb << "\n";
  131. 	// your code goes here
  132. 	return 0;
  133. }
Success #stdin #stdout 0.29s 5420KB
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Errors (A): 0
Errors (B): 0
https://ideone.com/lp84BW
language:
C++ (gcc 8.3)
created:
3 years ago
visibility:
secret

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