题解 | #矩阵乘法计算量估算#

const readline = require("readline");

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
});
let arr = [],
    index: number;
rl.on("line", function (line) {
    if (index === undefined) {
        index = Number(line);
    } else if (index !== 0) {
        index--;
        arr.push(line.split(" ").map((a) => Number(a)));
    } else {
        let stack = [],
            res = 0;

        for (let i = 0; i < line.length; i++) {
            if (line[i] === "(") continue;
            if (line[i] === ")") {
                const num1 = stack.pop();
                const num2 = stack.pop();
                // console.log(num1, num2);
                res = res + num1[0] * num1[1] * num2[0];
                stack.push([num2[0], num1[1]]);
                // console.log(stack, res);
            } else {
                stack.push(arr.shift());
                // console.log(stack);
            }
        }
        console.log(res);
    }
});