题解 | #挑7#

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void (async function () {
    // Write your code here
    let n;
    while ((line = await readline())) {
        n = +line;
    }
    let count = 0;
    for (let i = 7; i <= n; i++) {
        if (i % 7 == 0 || i.toString().indexOf("7") >= 0) {
            count++;
        }
    }
    console.log(count);
})();