CSP-201903-2-二十四点
作者:互联网
二十四点(传送门)
这道题比较绕,刚开始暴力破解,步骤有点多,后来有使用栈来解决,比较简单
输入:
10
9+3+4x3
5+4x5x5
7-9-9+8
5x6/5x4
3+5+7+9
1x1+9-9
1x9-5/9
8/5+6x9
6x7-3x6
6x4+4/5
输出:
Yes
No
No
Yes
Yes
No
No
No
Yes
Yes
满分代码1------------------------------暴力破解
#include <bits/stdc++.h>
using namespace std;
int n;
int result = 0;
bool judge[102];
string str;
int call(int a,int b,char c){
int res;
switch(c){
case 'x':
res=a*b;
break;
case '/':
res=a/b;
break;
case '+':
res=a+b;
break;
case '-':
res=a-b;
break;
}
return res;
}
bool cal(){
char c[6];
int coun = 0;
int j = -1;
c[1]=str[1];c[3]=str[3];c[5]=str[5];
for(int i = 1; i < 6; i+=2){
if(c[i]=='x' || c[i]=='/'){
c[i-1] = '1';
coun++;
}else{
c[i-1] = '0';
}
}
if(coun == 3 || coun == 0){ //例1+2+3+4 1*2*3*4 1/2/3/4
result = call(str[0]-'0',str[2]-'0',str[1]);
result = call(result,str[4]-'0',str[3]);
result = call(result,str[6]-'0',str[5]);
}else{
if(coun == 1){
for(int i = 1; i < 6; i+=2){
if(c[i-1] == '1'){
result = call(str[i-1]-'0',str[i+1]-'0',str[i]);
j = i;
}
}
if(j == 1){ //例1*2+3-4
result = call(result,str[4]-'0',str[3]);
result = call(result,str[6]-'0',str[5]);
}else if(j == 3){ //例1+2*3-4
result = call(str[0]-'0',result,str[1]);
result = call(result,str[6]-'0',str[5]);
}else{ //例1+2+3*4
int res = call(str[0]-'0',str[2]-'0',str[1]);
result = call(res,result,str[3]);
}
}else{
for(int i = 1; i < 6; i+=2){
if(c[i-1] == '0'){
j = i;
}
}
if(j == 1){ //例 1+2*3/4
result = call(str[2]-'0',str[4]-'0',str[3]);
result = call(result,str[6]-'0',str[5]);
result = call(str[0]-'0',result,str[1]);
}else if(j == 3){ //例 1*2+3*4
int res = call(str[0]-'0',str[2]-'0',str[1]);
result = call(str[4]-'0',str[6]-'0',str[5]);
result = call(res,result,str[3]);
}else{ //例 1*2*3-4
result = call(str[0]-'0',str[2]-'0',str[1]);
result = call(result,str[4]-'0',str[3]);
result = call(result,str[6]-'0',str[5]);
}
}
}
if(result == 24){
return true;
}
return false;
}
int main(){
cin >> n;
for(int i = 0 ; i < n; i++){
cin >> str;
if(cal()){
judge[i] = true;
}
}
for(int i = 0; i < n; i++){
if(judge[i]){
cout << "Yes\n";
}else{
cout << "No\n";
}
}
return 0;
}
满分代码2------------------------------使用栈实现-------------------------参考别人代码才知道使用栈
#include <iostream>
using namespace std;
int main(){
int n, num[5], temp;//行数 - num[栈顶,--]
char op[5]; //运算符
num[0] = 0; //初始化操作数栈
op[0] = 0; //初始化运算符栈
cin>>n;
int result[n];
for(int i=0; i<n; ++i){
for(int j=0; j<7; ++j){
if(j%2 == 0){ //操作数进栈
cin>>num[++num[0]];
if (op[op[0]] == '-') //如果运算符栈顶为 - 则将操作数转换 +(-x)
num[num[0]] *= -1;
else if (op[op[0]] == 'x'){ //需要x运算
temp = num[num[0]] * num[num[0]-1];
num[--num[0]] = temp;
--op[0];
}
else if(op[op[0]] == '/'){ //需要/运算
temp = num[num[0]-1] / num[num[0]];
num[--num[0]] = temp;
--op[0];
}
}
else{ //运算符进栈
cin>>op[++op[0]];
}
}
while(op[0] > 0){ //将剩余+号运算完
temp = num[num[0]] + num[num[0]-1];
num[--num[0]] = temp;
--op[0];
}
if(num[1] == 24) //判定结果
result[i] = 1;
else
result[i] = 0;
num[0] = 0; //初始化操作数栈
}
for(int i=0; i<n; ++i){ //打印结果
if(result[i] == 1)
cout<<"Yes\n";
else
cout<<"No\n";
}
return 0;
这里是题目O(∩_∩)O,欢迎大家留言,有空的话可以点个赞哦(#^ . ^#)
试题编号: | 201903-2 |
---|---|
试题名称: | 二十四点 |
时间限制: | 1.0s |
内存限制: | 256.0MB |
问题描述: |
标签:二十四点,int,num,call,result,str,op,CSP,201903 来源: https://blog.csdn.net/weixin_44635198/article/details/104716267