Python/Go/Java 算法常用模板、数据结构

记录一些个人在刷leetcode和CF中用的比较多的语法

初始化数组

Golang

go语言中定义二维数组和初始化比较特殊，需要先初始化行数再初始化列，定义一个mxn数组：：

mat := make([][]int, m)
for i := range mat {
	mat[i] = make([]int, n)
}

Python

定义一个mxn数组：

mat = [[0] * n for _ in range(m)]

本文来自博客园，作者：Jayvee，转载请注明原文链接： https://www.cnblogs.com/cenjw/p/java-algorithm-competition-input-model.html

输入输出

GO

package main

import (
  "bufio"
  "fmt"
  "os"
)

var reader *bufio.Reader = bufio.NewReader(os.Stdin)
var writer *bufio.Writer = bufio.NewWriter(os.Stdout)
func printf(f string, a ...interface{}) { fmt.Fprintf(writer, f, a...) }
func scanf(f string, a ...interface{}) { fmt.Fscanf(reader, f, a...) }

func main() {
  // STDOUT MUST BE FLUSHED MANUALLY!!!
  defer writer.Flush()

  var a, b int
  scanf("%d %d\n", &a, &b)
  printf("%d\n", a+b)
}

Java

实例化后调用即可。

class Read{
    private BufferedReader bf;
    private StringTokenizer st;
    public Read(){
        bf=new BufferedReader(new InputStreamReader(System.in));
        st=new StringTokenizer("");
    }
    public String nextLine() throws IOException{
        return bf.readLine();
    }
    public String next() throws IOException{
        while(!st.hasMoreTokens()){
            st=new StringTokenizer(bf.readLine());
        }
        return st.nextToken();
    }
    public int nextInt() throws IOException{
        return Integer.parseInt(next());
    }
    public long nextLong() throws IOException{
        return Long.parseLong(next());
    }
    public double nextDouble() throws IOException{
        return Double.parseDouble(next());
    }
    public BigInteger nextBigInteger() throws IOException{
        return new BigInteger(next());
    }
}