2661. 找出叠涂元素

2661. 找出叠涂元素

• 难度: medium
• 原始链接: https://leetcode.cn/problems/first-completely-painted-row-or-column
• 标签: 哈希

解法一: 哈希

go

func firstCompleteIndex(arr []int, mat [][]int) int {
    m := len(mat)
    n := len(mat[0])
    type point struct {
        x int
        y int
    }
    hash := make([]point, m * n + 1)
    for i := 0; i < m; i++ {
        for j := 0; j < n; j++ {
            hash[mat[i][j]] = point{
                x: i,
                y: j,
            }
        }
    }
    rows := make([]int, m)
    cols := make([]int, n)
    for i, num := range arr {
        r, c := hash[num].x, hash[num].y
        rows[r]++
        cols[c]++
        if rows[r] == n || cols[c] == m {
            return i
        }
    }
    return -1
}