题解 | #挑7#

while(line = readline()) {
    const num = parseInt(line);
    let count = 0;
    for (let i = 1; i <= num; i++) {
        if (isCludesSeven(i.toString()) || isSevenX(i)) {
            count++;
        }
    }
    print(count);
    
}

function isCludesSeven(str) {
    return /[7]/.test(str);
}

function isSevenX(num) {
    return num % 7 == 0;
}