LeetCode之Score After Flipping Ma
2019-01-01 本文已影响0人
糕冷羊
问题:
We have a two dimensional matrix A where each value is 0 or 1.
A move consists of choosing any row or column, and toggling each value in that row or column: changing all 0s to 1s, and all 1s to 0s.
After making any number of moves, every row of this matrix is interpreted as a binary number, and the score of the matrix is the sum of these numbers.
Return the highest possible score.
方法:
使最终结果最大一共需要做两部操作:
1)遍历所有行的第一个元素,如果为0则反转该行,保证每个二进制数的最高位都为1
2)遍历所有列(不包含首列,因为首列为最高位),如果该列0的个数多于一半则反转该列
经过如上两部操作之后则矩阵的结果即为最大
具体实现:
import kotlin.math.abs
class ScoreAfterFlippingMatrix {
fun matrixScore(A: Array<IntArray>): Int {
for (i in A.indices) {
if (A[i][0] == 0) {
for (j in A[0].indices) {
A[i][j] = abs(A[i][j] - 1)
}
}
}
for (j in 1..A[0].lastIndex) {
var zeroNum = 0
for (i in A.indices) {
if (A[i][j] == 0) {
zeroNum++
}
}
if (zeroNum * 2 > A.size) {
for (i in A.indices) {
A[i][j] = abs(A[i][j] - 1)
}
}
}
var sum = 0
for (i in A.indices) {
for (j in A[0].indices) {
sum += A[i][j] shl (A[0].lastIndex - j)
}
}
return sum
}
}
fun main(args: Array<String>) {
val array = arrayOf(intArrayOf(0, 0, 1, 1), intArrayOf(1,0 ,1, 0), intArrayOf(1, 1, 0, 0))
// val array = arrayOf(intArrayOf(0, 1), intArrayOf(1,1))
val scoreAfterFlippingMatrix = ScoreAfterFlippingMatrix()
val result = scoreAfterFlippingMatrix.matrixScore(array)
print("result: $result")
}
有问题随时沟通