31. 탄화수소 질량 [코드구현력 기르기]

나의정답.

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>

using namespace std;

int main(int argc, char** argv) {
	//freopen("input.txt", "rt", stdin);

	char formula[100];
	int cIdx = -1;
	int hIdx = -1;
	bool C = false;
	bool H = false;
	int cnt = 0;
	int Cnum = 0;
	int Hnum = 0;
	int res;
	
	
	for(int i = 0 ; i < 100 ; i++){
		scanf("%c", &formula[i]);
		cnt++;
		
		if(formula[i] == 'C' || formula[i] == 'c')
			cIdx = i;
		else if(formula[i] == 'H' || formula[i] == 'h')
			hIdx = i;
		else if(formula[i] == 10)
			break;
	}	
	
	for(int i = 0 ; i < cnt ; i++){
		if(formula[i] == 'C' || formula[i] == 'c'){
			C = true;
			H = false;
		}
		else if(formula[i] == 'H' || formula[i] == 'h'){
			C = false;
			H = true;	
		}
		
		if(C == true && (formula[i] >= 48 && formula[i] <= 57)){
			Cnum *= 10;
			Cnum += formula[i] - '0';
		}
		else if(H == true && (formula[i] >= 48 && formula[i] <= 57)){
			Hnum *= 10;
			Hnum += formula[i] - '0';
		}
		else if(C == true && !(formula[cIdx + 1] >= 48 && formula[cIdx+1] <= 57)){
			Cnum = 1;
		}
		else if(H == true && !(formula[hIdx + 1] >= 48 && formula[hIdx+1] <= 57)){
			Hnum = 1;
		}
	}
	
	res = Cnum * 12 + Hnum * 1;
	printf("%d", res);
}