T.T.T.#2: Equal to 24

t-dot-t-t-number-2-equal-to-24/prepare_data.js

@@ -0,0 +1,55 @@
+
+function equalTo24(a,b,c,d) {
+  // const ops = [
+  //   (a, b) => a + b,
+  //   (a, b) => a - b,
+  //   (a, b) => a * b,
+  //   (a, b) => a / b
+  // ];
+  const ops = [
+    (a, b) => `(${a}+${b})`,
+    (a, b) => `(${a}-${b})`,
+    (a, b) => `(${a}*${b})`,
+    (a, b) => `(${a}/${b})`,
+  ];
+  const opsLen = ops.length;
+  const arr = [a, b, c, d];
+  let res = [];
+  for (let i = 0; i < 3; ++i) {    
+    for (let iop = 0; iop < opsLen; ++iop) {
+      for (let j = 0; j < 2; ++j) {
+        for (let jop = 0; jop < opsLen; ++jop) {
+          for (let kop = 0; kop < opsLen; ++kop) {
+            let n = [...arr.slice(0, i), ops[iop](arr[i], arr[i+1]), ...arr.slice(i+2)];
+            n = [...n.slice(0, j), ops[jop](n[j], n[j+1]), ...n.slice(j+2)];
+            const resStr = ops[kop](n[0], n[1]);
+            if (eval(resStr) === 24) {
+              res.push(resStr);
+            }
+          }
+        }
+      }
+    }
+  }
+  return res;
+}
+
+let res = [];
+
+for (let i = 1; i <= 13; ++i) {
+  for (let j = 1; j <= 13; ++j) {
+    for (let k = 1; k <= 13; ++k) {
+      for (let l = 1; l <= 13; ++l) {
+        let arr = [i, j, k, l];
+        arr.sort((a, b) => a - b);
+        let codes = equalTo24(i, j, k, l);
+        if (codes.length) {
+          if (!res[arr[0]]) res[arr[0]] = [];
+          if (!res[arr[0]][arr[1]]) res[arr[0]][arr[1]] = [];
+          if (!res[arr[0]][arr[1]][arr[2]]) res[arr[0]][arr[1]][arr[2]] = [];
+          if (!res[arr[0]][arr[1]][arr[2]][arr[3]]) res[arr[0]][arr[1]][arr[2]][arr[3]] = codes[0];
+        }
+      }
+    }
+  }
+}