yr4 function

int yr4(
  1. int year
)

Returns a four digit year from year which may be only 2 digits, assuming that anything 70 or more means 19xx and under 70 means 20xx.

Implementation

int yr4(int year) {
  if (year > 1000) return year;
  if (year > 69) return 1900 + year;
  return 2000 + year;
}