int main(int argc, char** argv) {
FILE* fp;
if(argc != 2) {
printf("USAGE: TelephoneWords <fileContainingTestVectors>\n");
return 1;
}
fp = fopen(argv[1], "r");
if(fp == NULL) {
printf("Failed to open the input file '%s' for reading!\n", argv[1]);
return 2;
}
while(!feof(fp)) {
numLetters = 0;
firstWord = true;
do {
if(feof(fp)) {
break;
}
fscanf(fp, "%c", &(digits[numLetters]));
++numLetters;
} while(digits[numLetters-1] != '\n');
--numLetters;
if(numLetters <= 0) {
break;
}
printTelephoneWords();
printf("\n");
}
fclose(fp);
return 0;
}
int main(){
// O(3^n) complexity
int phoneNum[] = {4, 9, 7, 1, 9, 2, 7};
printTelephoneWords(phoneNum);
printTelephoneWords2(phoneNum);
}
void printTelephoneWords(int start=0) {
if(start == numLetters) {
if(!firstWord) {
printf(",");
}
for(int i=0;i<numLetters;++i) {
printf("%c", str[i]);
}
firstWord = false;
return;
}
int d = char2digit(digits[start]);
char* letters = words[d];
while(*letters != '\0') {
str[start] = *letters;
printTelephoneWords(start+1);
++letters;
}
}