백준 8595번 히든넘버

#include <iostream>
#include <math.h>

using namespace std;

bool is_num(char a) {
	if (a == '0' || a == '1' || a == '2' || a == '3' || a == '4' || a == '5' || a == '6' || a == '7' || a == '8' || a == '9')
		return true;
	else
		return false;
}

int main() {
	long long  temp = 0, result = 0;
	int length, jump = 1;
	cin >> length;
	char* word = new char[length+1];
	cin >> word;
	
	for (int i = length; i >= 0; i--) {
		if (is_num(word[i])) {
			temp += (word[i] - '0') * jump;
			jump *= 10;
		}
		if (i == 0 || !is_num(word[i])) {
			result += temp;
			temp = 0;
			jump = 1;
		}
	}
	cout << result;

	return 0;
}