【牛客網】秋招前最後一次模擬

這次的編程題，個人感覺比較簡單。我做的全是字符串類型的型。

第一題：DNA片段

var readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    terminal:false
});
rl.on('line', function(line){ // javascript每行數據的回調接口
  var stringDNA = line;
  var length = stringDNA.length;
  var char;var temp = 0;
  var max = 0;
  for(var i =0 ;i< length ; i++){
    char = stringDNA[i];
    if(char == "A" || char == "T" || char == "C" || char == "G"){
      temp++;
    }else{
      max = max>temp?max:temp;
      temp = 0;
    }
  }
  max = max>temp?max:temp;
  console.log(max);
});

第二題：最長偶串

var readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    terminal:false
});
var x = 0, a = str[0];
  x = str.indexOf(a);
  // 兩段字符串是否相等
  if(x > str.length/2){
    return 1;
  }
  var i = 0,indexs = [];
  while(i<str.length/2 && i > -1){
    indexs.push(i);
    i = str.indexOf(a,i+1);  
  }
  // console.log(indexs); // 
  if(indexs.length < 1){return 1;};
  for(var i = indexs.length - 1 ; i>0; i--){
    // console.log(str.substr(indexs[i],indexs[i]));//
    // console.log(str.substr(0,indexs[i]));//
    if(str.substr(indexs[i],indexs[i]) == str.substr(0,indexs[i])){
      // console.log("i:",indexs[i]);//
      return indexs[i]*2;
    }
  }
  return 1;
  // return n;
}

第三題：最少迴文串

var readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    terminal:false
});

rl.on('line', function(line){ // javascript每行數據的回調接口
  console.log(findMax(line));
});
function findMax(str){
  var sum = {};

  for(var i =0;i<str.length ; i++){
    sum[str[i]] = sum[str[i]] ? sum[str[i]]+1 : 1;
  }

  // pingjie 
  var duoyu = 0;
  for(var key in sum){
    // console.log(key,sum[key]);
    if(sum[key]%2){
      duoyu ++;
    }
  }
  return duoyu;
}