数学运算

2025-07-09 19:55:36

字符串相加

给定两个字符串形式的正数相加

add.ts

test.ts

          function add
(a
: string, b
: string) {
  let [intA
, decA
 = ''] = a
.split
('.')
  let [intB
, decB
 = ''] = b
.split
('.')

  const maxIntLen
 = Math
.max
(intA
.length
, intB
.length
)
  const maxDecLen
 = Math
.max
(decA
.length
, decB
.length
)

  intA
 = intA
.padStart
(maxIntLen
, '0')
  intB
 = intB
.padStart
(maxIntLen
, '0')
  decA
 = decA
.padEnd
(maxDecLen
, '0')
  decB
 = decB
.padEnd
(maxDecLen
, '0')

  let carry
 = 0

  let decimal
 = ''
  for (let i
 = maxDecLen
 - 1; i
 >= 0; i
--) {
    const sum
 = Number
(decA
[i
]) + Number
(decB
[i
]) + carry
    decimal
 = (sum
 % 10) + decimal
    carry
 = Math
.floor
(sum
 / 10)
  }

  let integer
 = ''
  for (let i
 = maxIntLen
 - 1; i
 >= 0; i
--) {
    const sum
 = Number
(intA
[i
]) + Number
(intB
[i
]) + carry
    integer
 = (sum
 % 10) + integer
    carry
 = Math
.floor
(sum
 / 10)
  }

  if (carry
 > 0) integer
 = carry
 + integer
  decimal
 = decimal
.replace
(/0+$/, '')

  return decimal
 ? `${integer
}.${decimal
}` : integer
}

字符串相加