자동완성

#include <stdio.h>
#include <string.h>

#define MAXNODES  27
#define MAXLAYERS 100
#define COL(a)  ( a - 'a' + 1 )
#define IsLayer(a) ( ( a > 0 ) && (a < MAXLAYERS ) )

#define NUMOFWORDS 37
#define NUMOFLOOKUPWORDS 15

char * lookupwords[NUMOFLOOKUPWORDS] = {
	"an",
	"a",
	"c",
	"ca",
	"co",
	"o",
	"or",
	"s",
	"t",
	"to",
	"y",
	"yo",
	"you",
	"i",
	"in"
};

char * words[NUMOFWORDS] = {
	"and",
	"and",
	"codepad",
	"org",
	"is",
	"o", /*"an",*/
	"online",
	"compiler",
	"interpreter",
	"a",
	"simple",
	"collaboration",
	"tool",
	"paste",
	"your",
	"code",
	"below",
	"codepad",
	"will",
	"run",
	"it",
	"and",
	"give",
	"you",
	"a",
	"short",
	"url",
	"you",
	"can",
	"use",
	"to",
	"share",
	"it",
	"in",
	"chat",
	"or",
	"email"
};

typedef struct _column {
	union { char * pstr; int nlayer; } _field;
} column, * pcolumn, ** ppcolumn;

column g_Tbl[MAXLAYERS][MAXNODES];
int g_UnusedLayer=0;

void PrintLayers() {
	int i=1,j=0;
	for(i=1;i<g_UnusedLayer;i++) {
		for(j=0;j<MAXNODES;j++) {
			printf ("i: %3d, j: %c >> ", i, j?'a'+j-1:'_'); 
			if ( ! IsLayer(g_Tbl[i][j]._field.nlayer) && g_Tbl[i][j]._field.nlayer)
				printf("%s\n", g_Tbl[i][j]._field.pstr);
			else if ( IsLayer(g_Tbl[i][j]._field.nlayer) )
				printf("[%d]\n", g_Tbl[i][j]._field.nlayer);
			else 
				printf("\n");
		}
		getchar();
	}
}

void PrintLayer(int nlayer) {
	int j;
	if(nlayer==0) return;
	else {
		for(j=0;j<MAXNODES;j++) {
			if ( ! IsLayer(g_Tbl[nlayer][j]._field.nlayer) && g_Tbl[nlayer][j]._field.nlayer)
				printf("Candidate >> %s\n", g_Tbl[nlayer][j]._field.pstr);
			else
				PrintLayer(g_Tbl[nlayer][j]._field.nlayer);
		}
	}
	return;
}

void FindCandidates(char *word) {
	int i=1,j=0,nlenword,col;
	nlenword=strlen(word);
	while (word[j]) {
		col=COL(word[j]);
		if ( g_Tbl[i][col]._field.nlayer == 0 ) {
			printf("No Candidates.\n");
			return;
		}
		else if ( !IsLayer(g_Tbl[i][col]._field.nlayer) 
			&& g_Tbl[i][col]._field.nlayer) {
			printf("Candidate >> %s\n", g_Tbl[i][col]._field.pstr);
			return;
		}
		else if (IsLayer(g_Tbl[i][col]._field.nlayer))
			i = g_Tbl[i][col]._field.nlayer;
		j++;
	}

	PrintLayer(i);

	return;
}

void Add(char * word) {
	int i=1,j=0,nlenword;
	char * prevword;
	int col;
	nlenword=strlen(word);
	while (word[j]) {
		col=COL(word[j]);
		if (g_Tbl[i][col]._field.nlayer == 0) {
			g_Tbl[i][col]._field.pstr = word;
			if( i > g_UnusedLayer ) {
				if(g_UnusedLayer < MAXLAYERS)
					g_UnusedLayer = i+1;
			}
			return;
		}
		else if( IsLayer(g_Tbl[i][col]._field.nlayer) ) {
			i = g_Tbl[i][col]._field.nlayer;
		}
		else if( ! strcmp (g_Tbl[i][col]._field.pstr, word) ) {
			return;
		}
		else if( j < nlenword ) {
			prevword = g_Tbl[i][col]._field.pstr;
			g_Tbl[i][col]._field.nlayer = g_UnusedLayer;
			i = g_UnusedLayer;
			if(g_UnusedLayer < MAXLAYERS)
				g_UnusedLayer++;
			Add(prevword);
		}
		j++;
	}
	g_Tbl[i][0]._field.pstr = word;
	return;
};

#define __PRINT__
#undef  __PRINT__
#define __INTERACTIVE__
#undef  __INTERACTIVE__

int main(int argc, char * argv[]) {
	int i;
	char buf[128]="";
	memset(g_Tbl,0,sizeof(column)*MAXNODES*MAXLAYERS);

	for(i=0;i<NUMOFWORDS;i++) {
		Add(words[i]);

#ifdef __PRINT__
		system("cls");
		printf("- %s : g_UnusedLayer : %d - \n", words[i], g_UnusedLayer);
		PrintLayers();
#endif __PRINT__

	}

#ifdef __INTERACTIVE__
	do {
		printf("Lookup : ");
		fgets(buf, 127, stdin);
		buf[strlen(buf)-1]='\0';
		FindCandidates(buf);
	} while (strcmp(buf,"quit"));
#else 
	for(i=0;i<NUMOFLOOKUPWORDS;i++) {
		printf("-- %s --\n", lookupwords[i]);
		FindCandidates(lookupwords[i]);
	}
#endif __INTERACTIVE__

	return 0;
}