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Shortest common supersequence: Difference between revisions
→{{header|C}}
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<!-- This example is taken from the Wikipedia page. -->
=={{header|C}}==
The C99 code here isn't all that different from Levenstein distance calculation.
<lang c>#include <stdio.h>
#include <string.h>
typedef struct link link_t;
struct link {
int len;
char letter;
link_t *next;
};
// Stores a copy of a SCS of x and y in out. Caller needs to make sure out is long enough.
int scs(char *x, char *y, char *out)
{
int lx = strlen(x), ly = strlen(y);
link_t lnk[ly + 1][lx + 1];
for (int i = 0; i < ly; i++)
lnk[i][lx] = (link_t) {ly - i, y[i], &lnk[i + 1][lx]};
for (int j = 0; j < lx; j++)
lnk[ly][j] = (link_t) {lx - j, x[j], &lnk[ly][j + 1]};
lnk[ly][lx] = (link_t) {0};
for (int i = ly; i--; ) {
for (int j = lx; j--; ) {
link_t *lp = &lnk[i][j];
if (y[i] == x[j]) {
lp->next = &lnk[i+1][j+1];
lp->letter = x[j];
} else if (lnk[i][j+1].len < lnk[i+1][j].len) {
lp->next = &lnk[i][j+1];
lp->letter = x[j];
} else {
lp->next = &lnk[i+1][j];
lp->letter = y[i];
}
lp->len = lp->next->len + 1;
}
}
for (link_t *lp = &lnk[0][0]; lp; lp = lp->next)
*out++ = lp->letter;
return 0;
}
int main(void)
{
char x[] = "abcbdab", y[] = "bdcaba", res[128];
scs(x, y, res);
printf("SCS(%s, %s) -> %s\n", x, y, res);
return 0;
}</lang>
{{out}}
<pre>
SCS(abcbdab, bdcaba) -> abdcabdab
</pre>
=={{header|Tcl}}==
This example uses either of the <code>lcs</code> implementations from [[longest common subsequence#Tcl|here]], assumed renamed to <tt>lcs</tt>…
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