1let mat = [[1, 2, 1, 4, 8],[3, 7, 8, 5, 1],[8, 7, 7, 3, 1],[8, 1, 2, 7, 9]]
2let mat2 = [[1, 2, 5, 4, 8],[3, 7, 8, 5, 1],[8, 7, 5, 3, 1],[8, 1, 2, 5, 9]]
3function findCommonElement(matrix){
4    let m = new Map()
5    for(let i = 0; i< matrix.length; i++){
6        for(let j = 0; j< matrix[0].length; j++){
7            if(i===0){
8              m.set(matrix[i][j], 1)  
9            }else if(m.get(matrix[i][j]) === i){
10                m.set(matrix[i][j], i+1)  
11            }else{
12               continue
13            }
14        }
15    }
16    let element = []
17    for(const key of m.keys()){
18        console.log("m key===>",key)
19        if(m.get(key) ===  matrix.length){
20            element.push(key)
21        }
22    }
23    return element
24}
25
26console.log(findCommonElement(mat))
27console.log(findCommonElement(mat2))