From 6450445b8962745beb749a5ec7cadc61a62b114e Mon Sep 17 00:00:00 2001
From: Valentyn Kolesnikov <javadev75@gmail.com>
Date: Wed, 14 May 2025 04:39:48 +0300
Subject: [PATCH] Improved task 3337
---
.../Solution.java | 107 ++++++++----------
1 file changed, 46 insertions(+), 61 deletions(-)
diff --git a/src/main/java/g3301_3400/s3337_total_characters_in_string_after_transformations_ii/Solution.java b/src/main/java/g3301_3400/s3337_total_characters_in_string_after_transformations_ii/Solution.java
index e086d28bc..9657d090c 100644
--- a/src/main/java/g3301_3400/s3337_total_characters_in_string_after_transformations_ii/Solution.java
+++ b/src/main/java/g3301_3400/s3337_total_characters_in_string_after_transformations_ii/Solution.java
@@ -1,87 +1,72 @@
package g3301_3400.s3337_total_characters_in_string_after_transformations_ii;
// #Hard #String #Hash_Table #Dynamic_Programming #Math #Counting
-// #2024_10_29_Time_67_ms_(99.31%)_Space_45.4_MB_(45.83%)
+// #2025_05_14_Time_80_ms_(72.97%)_Space_45.62_MB_(24.32%)
import java.util.List;
public class Solution {
- public static final int MOD = 1000000007;
- public static final long M2 = (long) MOD * MOD;
- public static final long BIG = 8L * M2;
+ private static final int MOD = 1_000_000_007;
- public int lengthAfterTransformations(String s, int t, List<Integer> nums) {
- int[][] m = new int[26][26];
- for (int i = 0; i < 26; i++) {
- for (int j = 1; j <= nums.get(i); j++) {
- m[(i + j) % 26][i]++;
- }
- }
- int[] v = new int[26];
+ public int lengthAfterTransformations(String s, int t, List<Integer> numsList) {
+ int[][] localT = buildTransformationMatrix(numsList);
+ int[][] tPower = matrixPower(localT, t);
+ int[] freq = new int[26];
for (char c : s.toCharArray()) {
- v[c - 'a']++;
+ freq[c - 'a']++;
}
- v = pow(m, v, t);
- long ans = 0;
- for (int x : v) {
- ans += x;
+ long result = 0;
+ for (int i = 0; i < 26; i++) {
+ long sum = 0;
+ for (int j = 0; j < 26; j++) {
+ sum = (sum + (long) freq[j] * tPower[j][i]) % MOD;
+ }
+ result = (result + sum) % MOD;
}
- return (int) (ans % MOD);
+
+ return (int) result;
}
- // A^e*v
- private int[] pow(int[][] a, int[] v, long e) {
- for (int i = 0; i < v.length; i++) {
- if (v[i] >= MOD) {
- v[i] %= MOD;
- }
- }
- int[][] mul = a;
- for (; e > 0; e >>>= 1) {
- if ((e & 1) == 1) {
- v = mul(mul, v);
+ private int[][] buildTransformationMatrix(List<Integer> numsList) {
+ int[][] localT = new int[26][26];
+ for (int i = 0; i < 26; i++) {
+ int steps = numsList.get(i);
+ for (int j = 1; j <= steps; j++) {
+ localT[i][(i + j) % 26]++;
}
- mul = p2(mul);
}
- return v;
+ return localT;
}
- // int matrix*int vector
- private int[] mul(int[][] a, int[] v) {
- int m = a.length;
- int n = v.length;
- int[] w = new int[m];
- for (int i = 0; i < m; i++) {
- long sum = 0;
- for (int k = 0; k < n; k++) {
- sum += (long) a[i][k] * v[k];
- if (sum >= BIG) {
- sum -= BIG;
- }
+ private int[][] matrixPower(int[][] matrix, int power) {
+ int size = matrix.length;
+ int[][] result = new int[size][size];
+ for (int i = 0; i < size; i++) {
+ result[i][i] = 1;
+ }
+ while (power > 0) {
+ if ((power & 1) == 1) {
+ result = multiplyMatrices(result, matrix);
}
- w[i] = (int) (sum % MOD);
+ matrix = multiplyMatrices(matrix, matrix);
+ power >>= 1;
}
- return w;
+ return result;
}
- // int matrix^2 (be careful about negative value)
- private int[][] p2(int[][] a) {
- int n = a.length;
- int[][] c = new int[n][n];
- for (int i = 0; i < n; i++) {
- long[] sum = new long[n];
- for (int k = 0; k < n; k++) {
- for (int j = 0; j < n; j++) {
- sum[j] += (long) a[i][k] * a[k][j];
- if (sum[j] >= BIG) {
- sum[j] -= BIG;
- }
+ private int[][] multiplyMatrices(int[][] a, int[][] b) {
+ int size = a.length;
+ int[][] result = new int[size][size];
+ for (int i = 0; i < size; i++) {
+ for (int k = 0; k < size; k++) {
+ if (a[i][k] == 0) {
+ continue;
+ }
+ for (int j = 0; j < size; j++) {
+ result[i][j] = (int) ((result[i][j] + (long) a[i][k] * b[k][j]) % MOD);
}
- }
- for (int j = 0; j < n; j++) {
- c[i][j] = (int) (sum[j] % MOD);
}
}
- return c;
+ return result;
}
}