1题 交通拥塞路段。浮点数比较大小可能出现问题,最好转换成整数比较
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); int k = sc.nextInt(); int[] arr = new int[n]; for (int i = 0; i < n; ++i) { arr[i] = sc.nextInt(); } // 窗口范围[k,n], 平均值最大,次之窗口最宽 int[] preSum = new int[n + 1]; for (int i = 1; i<= n; ++i) { preSum[i] = preSum[i-1] + arr[i-1]; // preSum[i] = sum(arr[1..i)) } long sum = 0; int st = 0, ed = 0; // avg = sum / (ed - st) for (int i = 0; i <= n - k; ++i) { for (int j = i + k; j <= n; ++j) { long tmpSum = preSum[j] - preSum[i]; if (sum * (j - i) < tmpSum * (ed - st) // sum/(ed-st) < tmpSum/(j-i) || sum * (j - i) == tmpSum * (ed - st) && (j - i) > (ed - st)) { sum = tmpSum; ed = j; st = i; } } } System.out.println(st + " " + (ed - 1)); } }
import java.util.Scanner; public class Main { public static void main(String[] args) { int[][] changeCount = { {0, 4, 3, 3, 4, 3, 2, 3, 1, 2}, {4, 0, 5, 3, 2, 5, 6, 1, 5, 4}, {3, 5, 0, 2, 5, 4, 3, 4, 2, 3}, {3, 3, 2, 0, 3, 2, 3, 2, 2, 1}, {4, 2, 5, 3, 0, 3, 4, 3, 3, 2}, {3, 5, 4, 2, 3, 0, 1, 4, 2, 1}, {2, 6, 3, 3, 4, 1, 0, 5, 1, 2}, {3, 1, 4, 2, 3, 4, 5, 0, 4, 3}, {1, 5, 2, 2, 3, 2, 1, 4, 0, 1}, {2, 4, 3, 1, 2, 1, 2, 3, 1, 0}, {6, 2, 5, 5, 4, 5, 6, 3, 7, 6}, }; Scanner sc = new Scanner(System.in); String s = sc.next(); StringBuilder cache = new StringBuilder(); for (int d = 1; d <= s.length(); ++d) { // 宽度 cache.append(work(s, d, changeCount)).append(" "); } if (cache.length() > 0) { cache.deleteCharAt(cache.length() - 1); } System.out.println(cache); } private static int work(String s, int d, int[][] changeCount) { int count = 0; for (int i = 0; i < d; ++i) { count += changeCount[10][s.charAt(i) - '0']; } for (int i = 0; i < s.length() - d; ++i) { // 第i天 变化数 for (int j = i + 1; j <= i + d; ++j) { count += changeCount[s.charAt(j-1) - '0'][s.charAt(j) - '0']; } } return count; } } /* 说明: 所有测试数据正确率为 45%! 可以尝试再次完善代码,并调试,争取全部AC通过 温馨提示:有时候,申请大的全局数组会导致超时,如果有此类情况,请检查您的全局数组是否超过题目要求的内存大小。 排除这个错误后,再检查别的情况引起的超时错误:例如死循环、循环结束条件错误等,或者需要更好的算法! */打表代码
import java.util.Arrays; public class Main { public static void main(String[] args) { init(); for (int i = 0; i < changeCount.length; ++i) { System.out.println(Arrays.toString(changeCount[i])); } } static int[][] ligths = new int[][]{ // 0 1 2 3 4 5 6 {1, 1, 1, 1, 1, 1, 0}, // 0 {0, 0, 0, 0, 1, 1, 0}, // 1 {1, 0, 1, 1, 0, 1, 1}, // 2 {1, 0, 0, 1, 1, 1, 1}, // 3 {0, 1, 0, 0, 1, 1, 1}, // 4 {1, 1, 0, 1, 1, 0, 1}, // 5 {1, 1, 1, 1, 1, 0, 1}, // 6 {1, 0, 0, 0, 1, 1, 0}, // 7 {1, 1, 1, 1, 1, 1, 1}, // 8 {1, 1, 0, 1, 1, 1, 1}, // 9 }; static final int[][] changeCount = new int[11][10];; static void init() { for (int i = 0; i <= 9; ++i) { for (int j = i + 1; j <= 9; ++j) { changeCount[i][j] = changeCount[j][i] = calc(i, j); } } changeCount[10] = new int[]{6, 2, 5, 5, 4, 5, 6, 3, 7, 6}; } private static int calc(int num1, int num2) { int count = 0; for (int i = 0; i < 7; ++i) { count += ligths[num1][i] ^ ligths[num2][i]; } return count; } }
import java.util.Scanner; public class Main { public static void main(String[] args) { int[][] changeCount = { {0, 4, 3, 3, 4, 3, 2, 3, 1, 2}, {4, 0, 5, 3, 2, 5, 6, 1, 5, 4}, {3, 5, 0, 2, 5, 4, 3, 4, 2, 3}, {3, 3, 2, 0, 3, 2, 3, 2, 2, 1}, {4, 2, 5, 3, 0, 3, 4, 3, 3, 2}, {3, 5, 4, 2, 3, 0, 1, 4, 2, 1}, {2, 6, 3, 3, 4, 1, 0, 5, 1, 2}, {3, 1, 4, 2, 3, 4, 5, 0, 4, 3}, {1, 5, 2, 2, 3, 2, 1, 4, 0, 1}, {2, 4, 3, 1, 2, 1, 2, 3, 1, 0}, {6, 2, 5, 5, 4, 5, 6, 3, 7, 6}, }; Scanner sc = new Scanner(System.in); String s = sc.next(); StringBuilder cache = new StringBuilder(); for (int d = 1; d <= s.length(); ++d) { // 宽度 cache.append(work(s, d, changeCount)).append(" "); } if (cache.length() > 0) { cache.deleteCharAt(cache.length() - 1); } System.out.println(cache); } private static int work(String s, int d, int[][] changeCount) { int totalCount = 0; for (int i = 0; i < d; ++i) { totalCount += changeCount[10][s.charAt(i) - '0']; } if (d == s.length()) { return totalCount; } int count = 0; for (int j = 1; j <= d; ++j) { count += changeCount[s.charAt(j - 1) - '0'][s.charAt(j) - '0']; } totalCount += count; for (int j = 2; j < s.length() - d; ++j) { count += - changeCount[s.charAt(j-1) - '0'][s.charAt(j) - '0'] + changeCount[s.charAt(j+d-1) - '0'][s.charAt(j+d) - '0']; totalCount += count; } return totalCount; } }
3 题 时间复杂度得O(nlogn),哎
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