UVA-1586 分子量 题解答案代码 算法竞赛入门经典第二版

#include<cstdio>
#include<cstring>
#include<map>
using namespace std;

char s[90]; 
map<char, double> mp;

int main() {
  int t, a,i,j,k;
  double sum;
  char c; 
  mp['C'] = 12.01;
  mp['H'] = 1.008;
  mp['O'] = 16.0;
  mp['N'] = 14.01;
  
  scanf("%d", &t);
  while(t--) {
    scanf("%s", s);
    sum = 0;
    i = 0;
    while(s[i] != 0) {
      c = s[i];
      a = 0;
      while(isdigit(s[++i]))
        a = a * 10 + s[i] - '0';
      if(a == 0)
        sum += mp[c];
      else
        sum += mp[c] * a;
    }
    printf("%.3lf\n", sum);
  }
  return 0;
}