求L题数据验证
RT
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
string str;
int main() {
cin >> str;
double a = 0, b = 0;
bool f = false;
string ans;
for (int i = 0, len = str.size(); i < len;) {
if (str[i] == '=') {
f = true;
++i;
continue;
}
ll x = 0;
bool unk = false, sign = true;
if (str[i] == '+' || str[i] == '-') {
sign = str[i] == '+';
++i;
}
bool vis = false;
while (i < len && str[i] >= '0' && str[i] <= '9') {
vis = true;
x = x * 10 + str[i] - '0';
++i;
}
if (i < len && str[i] >= 'a' && str[i] <= 'z') {
unk = true;
string t;
while (i < len && str[i] >= 'a' && str[i] <= 'z') {
t.push_back(str[i]);
++i;
}
ans = t;
}
if (unk && !vis)
x = 1;
if (!sign)
x = -x;
// cout << unk << ";" << sign << ";" << x << endl;
if (unk)
b += !f ? x : -x;
else
a += f ? x : -x;
// cout << a << ":" << b << endl;
}
cout << ans;
printf("=%.3f\n", a / b);
return 0;
}
