#include <iostream> #include <cstdio> #include <cmath> #include <string> using namespace std; int main(){ // x是系数;v是值;等号左边equal为1,右边为-1;sign记录符号位;total记录系数或值的数字; int x = 0, v = 0, equal = 1, sign = 1, total = 0; // t记录未知数 char c, t; while (cin >> c)...