Balanced ternary: Difference between revisions
→{{header|C++}}
m (changed </scala> to </lang>) |
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Line 555:
65 : +-++-
-262023 : ----0+--0++0</pre>
=={{header|C}}==
{{trans|Perl}}
<lang c>#include <stdio.h>
#include <string.h>
void reverse(char *p) {
size_t len = strlen(p);
char *r = p + len - 1;
while (p < r) {
*p ^= *r;
*r ^= *p;
*p++ ^= *r--;
}
}
void to_bt(int n, char *b) {
static char d[] = { '0', '+', '-' };
static int v[] = { 0, 1, -1 };
char *ptr = b;
*ptr = 0;
while (n) {
int r = n % 3;
if (r < 0) {
r += 3;
}
*ptr = d[r];
*(++ptr) = 0;
n -= v[r];
n /= 3;
}
reverse(b);
}
int from_bt(const char *a) {
int n = 0;
while (*a != '\0') {
n *= 3;
if (*a == '+') {
n++;
} else if (*a == '-') {
n--;
}
a++;
}
return n;
}
char last_char(char *ptr) {
char c;
if (ptr == NULL || *ptr == '\0') {
return '\0';
}
while (*ptr != '\0') {
ptr++;
}
ptr--;
c = *ptr;
*ptr = 0;
return c;
}
void add(const char *b1, const char *b2, char *out) {
if (*b1 != '\0' && *b2 != '\0') {
char c1[16];
char c2[16];
char ob1[16];
char ob2[16];
char d[3] = { 0, 0, 0 };
char L1, L2;
strcpy(c1, b1);
strcpy(c2, b2);
L1 = last_char(c1);
L2 = last_char(c2);
if (L2 < L1) {
L2 ^= L1;
L1 ^= L2;
L2 ^= L1;
}
if (L1 == '-') {
if (L2 == '0') {
d[0] = '-';
}
if (L2 == '-') {
d[0] = '+';
d[1] = '-';
}
}
if (L1 == '+') {
if (L2 == '0') {
d[0] = '+';
}
if (L2 == '-') {
d[0] = '0';
}
if (L2 == '+') {
d[0] = '-';
d[1] = '+';
}
}
if (L1 == '0') {
if (L2 == '0') {
d[0] = '0';
}
}
add(c1, &d[1], ob1);
add(ob1, c2, ob2);
strcpy(out, ob2);
d[1] = 0;
strcat(out, d);
} else if (*b1 != '\0') {
strcpy(out, b1);
} else if (*b2 != '\0') {
strcpy(out, b2);
} else {
*out = '\0';
}
}
void unary_minus(const char *b, char *out) {
while (*b != '\0') {
if (*b == '-') {
*out++ = '+';
b++;
} else if (*b == '+') {
*out++ = '-';
b++;
} else {
*out++ = *b++;
}
}
*out = '\0';
}
void subtract(const char *b1, const char *b2, char *out) {
char buf[16];
unary_minus(b2, buf);
add(b1, buf, out);
}
void mult(const char *b1, const char *b2, char *out) {
char r[16] = "0";
char t[16];
char c1[16];
char c2[16];
char *ptr = c2;
strcpy(c1, b1);
strcpy(c2, b2);
reverse(c2);
while (*ptr != '\0') {
if (*ptr == '+') {
add(r, c1, t);
strcpy(r, t);
}
if (*ptr == '-') {
subtract(r, c1, t);
strcpy(r, t);
}
strcat(c1, "0");
ptr++;
}
ptr = r;
while (*ptr == '0') {
ptr++;
}
strcpy(out, ptr);
}
int main() {
const char *a = "+-0++0+";
char b[16];
const char *c = "+-++-";
char t[16];
char d[16];
to_bt(-436, b);
subtract(b, c, t);
mult(a, t, d);
printf(" a: %14s %10d\n", a, from_bt(a));
printf(" b: %14s %10d\n", b, from_bt(b));
printf(" c: %14s %10d\n", c, from_bt(c));
printf("a*(b-c): %14s %10d\n", d, from_bt(d));
return 0;
}</lang>
{{out}}
<pre> a: +-0++0+ 523
b: -++-0-- -436
c: +-++- 65
a*(b-c): ----0+--0++0 -262023</pre>
=={{header|C++}}==
<lang cpp>#include <iostream>
#include <string>
#include <climits>
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