[boj] 10844. 쉬운 계단 수 (node.js)
for (let i = 2; i <= N; i++) {
for (let j = 0; j <= 9; j++) {
if (j >= 1) dp[i][j] += dp[i - 1][j - 1];
if (j < 9) dp[i][j] += dp[i - 1][j + 1];
}
}
const readline = require("readline");
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
});
const solution = () => {
const N = input();
const dp = [];
dp[1] = [0, 1, 1, 1, 1, 1, 1, 1, 1, 1];
for (let i = 2; i <= N; i++) {
dp[i] = [];
for (let j = 0; j <= 9; j++) {
dp[i][j] = 0;
if (j >= 1) dp[i][j] += dp[i - 1][j - 1];
if (j < 9) dp[i][j] += dp[i - 1][j + 1];
dp[i][j] %= 1000000000;
}
}
console.log(dp[N].reduce((sum, elem) => sum + elem, 0) % 1000000000);
};
let line = 0;
const input = () => stdin[line++];
let stdin = [];
rl.on("line", function (line) {
stdin.push(line);
}).on("close", function () {
solution();
process.exit();
});