function readGraph(file::String)
    file = "C://Users//Antoine//Documents//MPRO//MLA//MLA//seance_3//instances//" * file
    if (!isfile(file))
        println("Je ne trouve pas le fichier")
        return
    end
    myFile=open(file)
    data=readlines(myFile)
    global n=parse(Int,data[1])
    global m=parse(Int,data[2])
    global adj=[]       #matrice d'adjacence
    global demande=zeros(n)     #demande
    for i in 3:3+m-1
        line=split(data[i]," ")
        u=parse(Int,line[1])
        #println("u : ",u+1)
        v=parse(Int,line[2])
        #println("v : ", v+1)
        push!(adj,v+1)
        push!(adj,u+1)
    end
    for i in 3+m:3+m+n-1
        line=split(data[i]," ")
        u=parse(Int,line[1])
        #println("u : ",u+1)
        d=parse(Int,line[2])
        #println("d: ",d)
        demande[u+1]=d
    end
    return n, m, adj, demande
end
