题解 | #矩阵乘法计算量估算#
矩阵乘法计算量估算
https://www.nowcoder.com/practice/15e41630514445719a942e004edc0a5b
const n = parseInt(readline())
const matrixArr = []
for(let i = 0;i<n;i++){
matrixArr.push(readline().split(' ').map(Number))
}
const str = readline()
const cal = (mat1,mat2) =>{
return mat1[0]*mat1[1]*mat2[1]
}
const oppArr = []
const numArr = []
let res = 0
for(let i = 0;i<str.length;i++){
if(str[i]==='('){
oppArr.push('(')
}
if(/[A-Z]/.test(str[i])){
numArr.push(str[i])
}
if(str[i] === ')'){
if(oppArr[oppArr.length-1]==='('){
const index1 = numArr.pop().charCodeAt()-65
const index2 = numArr[numArr.length-1].charCodeAt()-65
const mat1 = matrixArr[index2]
const mat2 = matrixArr[index1]
res += cal(mat1,mat2)
matrixArr[index2] = [matrixArr[index2][0],matrixArr[index1][1]]
oppArr.pop()
}
}
}
console.log(res)
