数列那个题刚开始我也是暴力，提示运行超时，然后突然发现一个规律：123，456， 789， 101112....每相邻三个一组的数据中必定有两个能够被三整除 var readline = require('readline'); const rl = readline.createInterface({ input: process.stdin, output: process.stdout, terminal:false }); function computed(n){ var g = Math.floor(n / 3); var l = n % 3 ; if(l == 0 || l== 1){ return g * 2; }else if(l == 2){ return g * 2 + 1; } } rl.on('line', function(line){ var tokens = line.split(' '); var start = Number(tokens[0]), end = Number(tokens[1]); console.log(computed(end) - computed(start - 1)); });