Create 2983-palindrome-rearrangement-queries.js

Author: everthis

2983-palindrome-rearrangement-queries.js

@@ -0,0 +1,70 @@
+function canMakePalindromeQueries(s, queries) {
+  const n = s.length
+  // Prefix sum (difference)
+  const psd = [0]
+  for (let i = 0, j = n - 1; i < j; i++, j--) {
+    psd.push(psd[psd.length - 1] + (s[i] !== s[j] ? 1 : 0))
+  }
+  // Prefix sum (count)
+  const cnt = new Array(26).fill(0)
+  const psc = [cnt.slice()]
+  for (const c of s) {
+    cnt[c.charCodeAt(0) - 'a'.charCodeAt(0)]++
+    psc.push([...cnt])
+  }
+  const ans = []
+  for (const q of queries) {
+    const a1 = q[0],
+      b1 = q[1] + 1,
+      a2 = n - q[0],
+      b2 = n - 1 - q[1]
+    const c1 = q[2],
+      d1 = q[3] + 1,
+      c2 = n - q[2],
+      d2 = n - 1 - q[3]
+    // No difference allowed outside the query ranges
+    if (
+      (min(a1, d2) && psd[min(a1, d2)]) ||
+      (n / 2 > max(b1, c2) && psd[Math.floor(n / 2)] - psd[max(b1, c2)]) ||
+      (d2 > b1 && psd[d2] - psd[b1]) ||
+      (a1 > c2 && psd[a1] - psd[c2])
+    ) {
+      ans.push(false)
+    } else {
+      // Intersection of query ranges in the lower half must equate to that in the upper half
+      const ix1 = psc[d1].map((val, i) => val - (psc[c1][i] || 0))
+      const ix2 = psc[b1].map((val, i) => val - (psc[a1][i] || 0))
+      if (a1 > d2) {
+        ix1.forEach(
+          (val, i) => (ix1[i] -= psc[Math.min(a1, c2)][i] - (psc[d2][i] || 0)),
+        )
+      }
+      if (c2 > b1) {
+        ix1.forEach(
+          (val, i) => (ix1[i] -= psc[c2][i] - (psc[Math.max(b1, d2)][i] || 0)),
+        )
+      }
+      if (c1 > b2) {
+        ix2.forEach(
+          (val, i) => (ix2[i] -= psc[Math.min(c1, a2)][i] - (psc[b2][i] || 0)),
+        )
+      }
+      if (a2 > d1) {
+        ix2.forEach(
+          (val, i) => (ix2[i] -= psc[a2][i] - (psc[Math.max(d1, b2)][i] || 0)),
+        )
+      }
+      ans.push(ix1.every((val, i) => val >= 0 && val === ix2[i]))
+    }
+  }
+  return ans
+}
+
+// Helper functions
+function min(a, b) {
+  return a < b ? a : b
+}
+
+function max(a, b) {
+  return a > b ? a : b
+}