#include<iostream> #include<algorithm> using namespace std; char ops[4] = {'+', '-', '*', '/'}; //两数计算 double cal(double db1, double db2, char op) { double result; switch (op) { case '+': result = db1 + db2; break; case '-': result = db1 - db2; break; case '*': result = db1 * db2; break;...