यहां लुकअप, जोड़ और स्थानांतरण का उपयोग करके एक समाधान है। लुकअप को गुणा की आवश्यकता नहीं है क्योंकि यह अन्य सरणी के पॉइंटर्स की एक सरणी है - इसलिए सही सरणी खोजने के लिए अतिरिक्त आवश्यकता है। फिर दूसरे मान का उपयोग करके आप पॉइंटर अंकगणित दोहरा सकते हैं और लुकअप परिणाम प्राप्त कर सकते हैं।
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv)
{
/* Note:As this is an array of pointers to an array of values, addition is
only required for the lookup.
i.e.
First part: lookup + a value -> A pointer to an array
Second part - Add a value to the pointer to above pointer to get the value
*/
unsigned char lookup[16][16] = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
{ 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 },
{ 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45 },
{ 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60 },
{ 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 },
{ 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90 },
{ 0, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105 },
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120 },
{ 0, 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, 126, 135 },
{ 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 },
{ 0, 11, 22, 33, 44, 55, 66, 77, 88, 99, 110, 121, 132, 143, 154, 165 },
{ 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180 },
{ 0, 13, 26, 39, 52, 65, 78, 91, 104, 117, 130, 143, 156, 169, 182, 195 },
{ 0, 14, 28, 42, 56, 70, 84, 98, 112, 126, 140, 154, 168, 182, 196, 210 },
{ 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195, 210, 225 }
};
unsigned short answer, mult;
unsigned char x, y, a, b;
x = (unsigned char)atoi(argv[1]);
y = (unsigned char)atoi(argv[2]);
printf("Multiple %d by %d\n", x, y);
answer = 0;
/* First nibble of x, First nibble of y */
a = x & 0xf;
b = y & 0xf;
mult = lookup[a][b];
answer += mult;
printf("Looking up %d, %d get %d - Answer so far %d\n", a, b, mult, answer);
/* First nibble of x, Second nibble of y */
a = x & 0xf;
b = (y & 0xf0) >> 4;
mult = lookup[a][b];
answer += mult << 4;
printf("Looking up %d, %d get %d - Answer so far %d\n", a, b, mult, answer);
/* Second nibble of x, First nibble of y */
a = (x & 0xf0) >> 4;
b = y & 0xf;
mult = lookup[a][b];
answer += mult << 4;
printf("Looking up %d, %d get %d - Answer so far %d\n", a, b, mult, answer);
/* Second nibble of x, Second nibble of y */
a = (x & 0xf0) >> 4;
b = (y & 0xf0) >> 4;
mult = lookup[a][b];
answer += mult << 8;
printf("Looking up %d, %d get %d - Answer so far %d\n", a, b, mult, answer);
return 0;
}
गुणा है अनुमति? – Kos
क्या '*' ऑपरेटर की अनुमति है? – ouah
hehecourse नहीं ... कोई गुणा नहीं "*" और कोई विभाजन नहीं। –