四则运算

include
include <string.h>
define size 10
using namespace std;

//含有一个二元算数式的三个值
typedef struct{
float x = 0,y = 0; //x,y为给定的随机数
float r = 0; //r为算数式结果
}Arithmetic;

Arithmetic choose(Arithmetic n);//选择函数，根据用户选择 识别将要进行的四则运算类型
float conversion(string input);//用户输入转换
bool judge(Arithmetic n);//结果判断
Arithmetic Addition();//加法运算
Arithmetic Subtraction();//减法运算
Arithmetic Multiplication();//乘法运算
Arithmetic Division();//除法运算

int main(int argc, const char * argv[]) {
int score = 0, cnt = 0;

// printf("请设置题目数量\n");
// scanf("%d",&cnt);

if (string(argv[1])=="-n") { //在terminals或者command中运行的时候，参数顺序存放在argv数组中
string c = argv[2];
cnt = stoi(c);
}

for (int i = 0; i<cnt; i++) {
Arithmetic t;
t = choose(t);
if (judge(t) == true) {
score+=10;
cout<<"恭喜您回答正确！\n";
} else {
cout<<"很抱歉您的答案不正确，再想想哦～\n";
}
}
printf("满分为：%d 您的得分为：%d分\n",cnt*10,score);

return 0;
}

//函数
//选择函数，根据用户选择识别将要进行的四则运算类型
Arithmetic choose(Arithmetic n){
int choose = 0;
cout<<"请选择您需要进行的四则运算类型\n"<<"1.加法\t2.减法\t3.乘法\t4.除法\n";
cin>>choose;
switch (choose) {
case 1:
n = Addition();
break;
case 2:
n = Subtraction();
break;
case 3:
n = Multiplication();
break;
case 4:
n = Division();
break;

default:
    break;

}

return n;
}

//转译用户输入结果
float conversion(string input){
bool flag = false, sign = false;
//flag标记用户输入中是否存在/号，有/号则true否则false
//sign标记用户输入是否为负数，是负数则true否则false
float a = 0, b = 0, result = 0;
for (int i = 0; i<input.length(); i++) {
if (input[i] != ‘/‘ && input[i] != ‘-‘) {
int num = input[i]-‘0‘; //将char型转换为int型
if (!flag) { //若果flag为false，则说明还未遇到/号
a *= 10; //a记录/号前的数值
a += num;
} else {
b *= 10; //b记录/号后的数值
b += num;
}
} else if (input[i] == ‘/‘){
flag = true;
} else {
sign = true;
}
}

if (flag && sign) { //既有/号，又是负值
result = -a/b;
} else if (flag && !sign){ //有/号，但为正值
result = a/b;
} else if (!flag && sign){ //没有有/号，但为负值
result = -a;
} else { //没有有/号，且为正值
result = a;
}
return result;
}

//判断对错函数
bool judge(Arithmetic n){
bool flag = false; //flag用于记录用户输入答案是否正确，正确return true，否则return false
string input;
cin>>input;
if (n.r == conversion(input))
flag = true;

return flag;
}

//Addition加法
Arithmetic Addition(){
Arithmetic n;
srand((unsigned)time(NULL));

if (rand()%2 == 0) {//若为0则进行整数四则运算，若为1则进行真分数的四则运算
n.x = rand()%size+1;
n.y = rand()%size+1;
n.r = n.x + n.y;
printf("%.0f + %.0f = ?\n",n.x,n.y);
} else {
float a,b,c,d;
a = rand()%size+1;
b = rand()%size+1;
c = rand()%size+1;
d = rand()%size+1;
if (a<b) { //需要保证数值是真分数
n.x = a/b;
} else if (ab){ //分子分母如果相同的话直接赋值为1
n.x = 1;
}else { //需要保证数值是真分数
n.x = b/a;
}
if (c<d) { //需要保证数值是真分数
n.y = c/d;
} else if (cd){ //分子分母如果相同的话直接赋值为1
n.y = 1;
}else { //需要保证数值是真分数
n.y = d/c;
}
n.r = n.x + n.y;

if (n.r==0) {   //结果为0说明两个真分数都是1/1
    printf("%.0f + %.0f = ?\n",n.x,n.y);
} else if (n.x==1){ //仅有一个真分数，一个1/1
    printf("%.0f + %.0f/%.0f = ?\n",n.x,c<d?c:d,c>d?c:d);
} else if (n.y==1){
    printf("%.0f/%.0f + %.0f = ?\n",a<b?a:b,a>b?a:b,n.y);
} else {        //除去其他可能，仅剩下两个数都是真分数的情况
    printf("%.0f/%.0f + %.0f/%.0f = ?\n",a<b?a:b,a>b?a:b,c<d?c:d,c>d?c:d);
}

}

return n;
}

//Subtraction减法
Arithmetic Subtraction(){
Arithmetic n;
srand((unsigned)time(NULL));

if (rand()%2 == 0) {//若为偶数则进行整数四则运算，若为奇数则进行真分数的四则运算
n.x = rand()%size+1;
n.y = rand()%size+1;
n.r = n.x - n.y;
printf("%.0f - %.0f = ?\n",n.x,n.y);
} else {
float a,b,c,d;
a = rand()%size+1;
b = rand()%size+1;
c = rand()%size+1;
d = rand()%size+1;
if (a<b) {
n.x = a/b;
} else if (ab){
n.x = 1;
}else {
n.x = b/a;
}
if (c<d) {
n.y = c/d;
} else if (cd){
n.y = 1;
}else {
n.y = d/c;
}
n.r = n.x - n.y;

if (n.r==0) {
    printf("%.0f - %.0f = ?\n",n.x,n.y);
} else if (n.x==1){
    printf("%.0f - %.0f/%.0f = ?\n",n.x,c<d?c:d,c>d?c:d);
} else if (n.y==1){
    printf("%.0f/%.0f - %.0f = ?\n",a<b?a:b,a>b?a:b,n.y);
} else {
    printf("%.0f/%.0f - %.0f/%.0f = ?\n",a<b?a:b,a>b?a:b,c<d?c:d,c>d?c:d);
}

}

return n;
}

//Multiplication乘法
Arithmetic Multiplication(){
Arithmetic n;
srand((unsigned)time(NULL));

if (rand()%2 == 0) {//若为偶数则进行整数四则运算，若为奇数则进行真分数的四则运算
n.x= rand()%size+1;
n.y= rand()%size+1;
n.r = n.x * n.y;
printf("%.0f * %.0f = ?\n",n.x,n.y);
} else {
float a,b,c,d;
a = rand()%size+1;
b = rand()%size+1;
c = rand()%size+1;
d = rand()%size+1;
if (a<b) {
n.x = a/b;
} else if (ab){
n.x = 1;
}else {
n.x = b/a;
}
if (c<d) {
n.y = c/d;
} else if (cd){
n.y = 1;
}else {
n.y = d/c;
}
n.r = n.x * n.y;

if (n.r==0) {
    printf("%.0f * %.0f = ?\n",n.x,n.y);
} else if (n.x==1){
    printf("%.0f * %.0f/%.0f = ?\n",n.x,c<d?c:d,c>d?c:d);
} else if (n.y==1){
    printf("%.0f/%.0f * %.0f = ?\n",a<b?a:b,a>b?a:b,n.y);
} else {
    printf("%.0f/%.0f * %.0f/%.0f = ?\n",a<b?a:b,a>b?a:b,c<d?c:d,c>d?c:d);
}

}

return n;
}

//Division除法
Arithmetic Division(){ //除法不需要考虑两个整数的，没有意义，直接两个真分数的除法
Arithmetic n;
srand((unsigned)time(NULL));

float a,b,c,d;
a = rand()%size+1;
b = rand()%size+1;
c = rand()%size+1;
d = rand()%size+1;
if (a<b) {
n.x = a/b;
} else if (ab){
n.x = 1;
}else {
n.x = b/a;
}
if (c<d) {
n.y = c/d;
} else if (cd){
n.y = 1;
}else {
n.y = d/c;
}
n.r = n.x / n.y;

if (n.r0) {
printf("%.0f / %.0f = ?\n",n.x,n.y);
} else if (n.x1){
printf("%.0f / %.0f/%.0f = ?\n",n.x,c<d?c:d,c>d?c:d);
} else if (n.y==1){
printf("%.0f/%.0f / %.0f = ?\n",a<b?a:b,a>b?a:b,n.y);
} else {
printf("%.0f/%.0f / %.0f/%.0f = ?\n",a<b?a:b,a>b?a:b,c<d?c:d,c>d?c:d);
}

return n;
}

四则运算

原文：https://www.cnblogs.com/227491gx/p/13945869.html