SOURCE

let one= [0,0]
let two = [0,0]
let three = [0,0]
let p = [one,two,three]
for(let n = 0;n<p.length;n++){
    let frontStart = parseFloat(p[n][0])
    let frontEnd = parseFloat(p[n][1])
    for(let j= n;j<p.length;j++){
        if(n!=j){
            let lastStart = parseFloat(p[j][0])
            let lastEnd = parseFloat(p[j][1])
            console.log(frontStart + "------" + frontEnd)
            console.log(lastStart + '----'+lastEnd)
            if((frontStart<lastStart && lastStart<frontEnd) || 
            (lastStart< frontStart && frontStart<lastEnd)||
            (frontStart<lastEnd && lastEnd<frontEnd) ||
            (lastStart< frontEnd && frontEnd<lastEnd)){
                console.log("有重合")
            }
            if(frontStart == lastStart && frontEnd == lastEnd){
                    console.log("有重合2")
            }
        }  
    }
}