题解 | #24点运算#
24点运算
https://www.nowcoder.com/practice/7e124483271e4c979a82eb2956544f9d
dfs 暴力
const readline = require("readline");
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
});
rl.on("line", function (line) {
let m = {
3: 3,
4: 4,
5: 5,
6: 6,
7: 7,
8: 8,
9: 9,
10: 10,
J: 11,
Q: 12,
K: 13,
A: 1,
2: 2,
};
let data = line.trim().split(" ");
let res = "NONE";
if (data.includes("joker") || data.includes("JOKER")) {
return console.log("ERROR");
}
// 深度遍历
function dfs(step, sum, arr, s) {
if (sum == 24 && step == 4) {
return (res = s);
} else {
step++;
for (let i = 0; i < arr.length; i++) {
let _arr = arr.slice();
_arr.splice(i, 1);
let num = m[arr[i]];
if (step == 1) {
dfs(step, num, _arr, `${arr[i]}`);
} else {
dfs(step, sum + num, _arr, `${s}+${arr[i]}`);
dfs(step, sum - num, _arr, `${s}-${arr[i]}`);
dfs(step, sum * num, _arr, `${s}*${arr[i]}`);
dfs(step, sum / num, _arr, `${s}/${arr[i]}`);
}
}
}
}
dfs(0, 0, data, "");
console.log(res);
});
