干得好。我刚刚写了这篇文章,并将其设为公共领域。
它将 unsigned bcd 转换为 unsigned int,反之亦然。使用 bcd2i() 将 BCD 转换为无符号整数,执行所需的任何数学运算,然后使用 i2bcd() 将数字恢复为 BCD。
unsigned int bcd2i(unsigned int bcd) {
unsigned int decimalMultiplier = 1;
unsigned int digit;
unsigned int i = 0;
while (bcd > 0) {
digit = bcd & 0xF;
i += digit * decimalMultiplier;
decimalMultiplier *= 10;
bcd >>= 4;
}
return i;
}
unsigned int i2bcd(unsigned int i) {
unsigned int binaryShift = 0;
unsigned int digit;
unsigned int bcd = 0;
while (i > 0) {
digit = i % 10;
bcd += (digit << binaryShift);
binaryShift += 4;
i /= 10;
}
return bcd;
}
// Thanks to EmbeddedGuy for bug fix: changed init value to 0 from 1
#include <iostream>
using namespace std;
int main() {
int tests[] = {81986, 3740, 103141, 27616, 1038,
56975, 38083, 26722, 72358,
2017, 34259};
int testCount = sizeof(tests)/sizeof(tests[0]);
cout << "Testing bcd2i(i2bcd(test)) on 10 cases" << endl;
for (int testIndex=0; testIndex<testCount; testIndex++) {
int bcd = i2bcd(tests[testIndex]);
int i = bcd2i(bcd);
if (i != tests[testIndex]) {
cout << "Test failed: " << tests[testIndex] << " >> " << bcd << " >> " << i << endl;
return 1;
}
}
cout << "Test passed" << endl;
return 0;
}
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