Update: 2020/03/02

Author: SunYufei

CCF/CCSP/2019/sql/std.py

@@ -1,6 +1,5 @@
 #!/usr/bin/python3
 #-*- coding=utf-8 -*-
-import sys
 import sqlite3
 
 db = sqlite3.connect(':memory:')

CCF/CSP/2017/17122.py

@@ -1,4 +1,3 @@
-from queue import Queue
 n, k = map(int, input().split())
 q = []
 for i in range(1, n + 1):

CodingInterviews/Fibonacci.java

@@ -0,0 +1,19 @@
+public class Fibonacci {
+    public static void main(String[] args) {
+        int n = 100;
+        System.out.println(fib(n));
+    }
+
+    private static int fib(int n) {
+        if (n <= 1)
+            return n;
+        long a = 0, b = 1;
+        long ans = 0;
+        for (int i = 2; i <= n; i++) {
+            ans = (a + b) % 1000000007;
+            a = b;
+            b = ans;
+        }
+        return (int) ans;
+    }
+}

CodingInterviews/RepeatNumber.java

@@ -0,0 +1,21 @@
+import java.util.HashSet;
+import java.util.Set;
+
+public class RepeatNumber {
+    public static void main(String[] args) {
+        int[] nums = { 2, 3, 1, 0, 2, 5, 3 };
+        System.out.println(findRepeatNumber(nums));
+    }
+
+    private static int findRepeatNumber(int[] nums) {
+        int repeat = -1;
+        Set<Integer> set = new HashSet<Integer>();
+        for (int num : nums) {
+            if (!set.add(num)) {
+                repeat = num;
+                break;
+            }
+        }
+        return repeat;
+    }
+}

CodingInterviews/ReplaceSpace.java

@@ -0,0 +1,17 @@
+public class ReplaceSpace {
+    public static void main(String[] args) {
+        String s = "We are happy.";
+        System.out.println(replaceSpace(s));
+    }
+
+    private static String replaceSpace(String s) {
+        StringBuilder ans = new StringBuilder();
+        for (char c : s.toCharArray()) {
+            if (c == ' ')
+                ans.append("%20");
+            else
+                ans.append(c);
+        }
+        return ans.toString();
+    }
+}