int main() {
int currentNum = 20;
while (!validNum(currentNum)) currentNum += 20;
printf("%d\n", currentNum);
return 0;
}
static int getIntFromString(char c, int * dest, int * i, int base, const char * src, int * j) {
if( c == cut ) {
return 1;
} else if( !validNum(c, base) ) {
return 0;
}
char chr = src[(*j)++];
int ret = getIntFromString(chr, dest, i, base, src, j);
if( isdigit(c) )
*dest += (c - '0') * pow(base, (*i)++);
else if( isupper(c) )
*dest += (c - 'A' + 10) * pow(base, (*i)++);
else
*dest += (c - 'a' + 10) * pow(base, (*i)++);
return ret;
}
static int getInt(char c, int * dest, int * i, int base) {
if( c == cut ) {
return 1;
} else if( !validNum(c, base) ) {
return 0;
}
char chr = getchar();
int ret = getInt(chr, dest, i, base);
if( isdigit(c) )
*dest += (c - '0') * pow(base, (*i)++);
else if( isupper(c) )
*dest += (c - 'A' + 10) * pow(base, (*i)++);
else
*dest += (c - 'a' + 10) * pow(base, (*i)++);
return ret;
}
int vsscanf(const char * src, const char * fmt, va_list args) {
int read = 0, i = 0, j = 0, type, state = CHAR;
int sign, hasSign, base;
char * str, * sdest;
char c;
while( fmt[i] != 0 ) {
switch( state ) {
case CHAR:
switch( fmt[i] ) {
case '%':
state = PERCENTAGE;
break;
case ' ':
default:
c = src[j++];
if( c != fmt[i] )
return read;
}
i++;
break;
case PERCENTAGE:
switch( fmt[i] ) {
case '%':
state = CHAR;
c = src[j++];
if( c != fmt[i] )
return read;
i++;
break;
case 'd':
state = GETINT;
type = DEC;
break;
case 'h':
case 'x':
state = GETINT;
type = HEX;
break;
case 'o':
state = GETINT;
type = OCT;
break;
case 'c':
state = GETCHAR;
break;
case 's':
state = GETSTRING;
break;
default:
return -1; //TODO: ERROR
}
break;
case GETINT:
base = 10;
hasSign = 0;
sign = 1;
i++;
cut = fmt[i++];
state = CHAR;
c = src[j++];
switch( c ) {
case '-':
sign = -1;
case '+':
c = src[j++];
hasSign = 1;
break;
}
if( hasSign && c == cut ) {
return read;
} else if( !hasSign && c == cut ) {
break;
}
if( type == OCT || type == HEX) {
if( c != '0' ) {
return read;
}
c = src[j++];
if( type == HEX ) {
if( c != 'x' )
return read;
c = src[j++];
base = 16;
} else
base = 8;
}
if( !validNum(c, base) ) {
return read;
} else {
int * dest = va_arg(args, int *);
int k = 0;
int ret;
*dest = 0;
ret = getIntFromString(c, dest, &k, base, src, &j);
*dest *= sign;
read++;
if( !ret ) {
return read;
}
}
break;
case GETCHAR:
state = CHAR;
c = src[j++];
if( !isgraph(c) )
return read;
*va_arg(args, char *) = c;
i++;
read++;
break;
case GETSTRING:
i++;
cut = fmt[i++];
state = CHAR;
c = src[j++];
sdest = va_arg(args, char *);
str = sdest;
while( c != cut && isgraph(c) ) {
*(sdest++) = c;
c = src[j++];
}
*sdest = 0;
if( (*str) )
read++;
if( c != cut )
return read;
break;
}
}
return read;
}
bool validTerm(const string &expr, int &L){
if (L >= expr.size()) return false;
if (expr[L] == '(') return validParen(expr, L);
else return validNum(expr, L);
}
