题解 | #挑7#

const readline = require('readline');

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function (line) {
    // 1、将输入的值保存未数值类型
    const num = line * 1
    let sum = 0
    // 2、循环判断是否符合要求
    for(let i = 1; i <= num; i++){
        // 是7的倍数或者包含7的
        if(i % 7 === 0 || (i+'').includes('7')) sum++
    }
    console.log(sum)
});