题解 | #走方格的方案数#

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
    while ((line = await readline())) {
        let tokens = line.split(" ");
        let n = parseInt(tokens[0]);
        let m = parseInt(tokens[1]);
        method(n + 1, m + 1);
    }
})();

function method(n, m) {
    let dp = new Array(n).fill(0).map(() => new Array(m));
    for (let i = 0; i < n; i++) {
        dp[i][0] = 1;
    }
    for (let i = 0; i < m; i++) {
        dp[0][i] = 1;
    }
    for (let i = 1; i < n; i++) {
        for (let j = 1; j < m; j++) {
            dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
        }
    }
    console.log(dp[n - 1][m - 1]);
}