URAL 1329 Galactic History (DFS)

#include<stdio.h>
#define MAX (40000 + 1)
int numOfMilestones;
typedef struct{
    int id;
    int next;
}NODE;
NODE sonArray[MAX];//used as adjacent list
int sonNum;
int headArray[MAX];
int root;
typedef struct{
    int nodeTime;
    int maxDescendantTime;
}NODETIME;
NODETIME nodeTimeArray[MAX];
int time;
int numOfQuaries;


void DFS(int father){
    time++;
    nodeTimeArray[father].nodeTime = time;
    nodeTimeArray[father].maxDescendantTime = time;
    int indexOfSon;
    for (indexOfSon = headArray[father]; indexOfSon != 0; indexOfSon = sonArray[indexOfSon].next){
        int son = sonArray[indexOfSon].id;
        DFS(son);
        if (nodeTimeArray[son].maxDescendantTime > nodeTimeArray[father].maxDescendantTime){
            nodeTimeArray[father].maxDescendantTime = nodeTimeArray[son].maxDescendantTime;
        }
    }
}
int main(){

    scanf("%d", &numOfMilestones);
    int indexOfMilestone;
    for (indexOfMilestone = 1; indexOfMilestone <= numOfMilestones; indexOfMilestone++){
        int son, father;
        scanf("%d %d", &son, &father);
        if (father == -1){
            root= father;
        }
        sonNum++;
        sonArray[sonNum].id = son;
        sonArray[sonNum].next = headArray[father];
        headArray[father] = sonNum;
    }
    DFS(root);
    scanf("%d", &numOfQuaries);
    int indexOfQuary;
    for (indexOfQuary = 1; indexOfQuary <= numOfQuaries; indexOfQuary++){
        int one, another;
        scanf("%d %d", &one, &another);
        if (nodeTimeArray[one].nodeTime < nodeTimeArray[another].nodeTime &&
            nodeTimeArray[one].maxDescendantTime >= nodeTimeArray[another].nodeTime){

                printf("1\n");
        } else if (nodeTimeArray[another].nodeTime < nodeTimeArray[one].nodeTime &&
                   nodeTimeArray[another].maxDescendantTime >= nodeTimeArray[one].nodeTime){

                    printf("2\n");
                } else {
                    printf("0\n");
                }
    }
    return 0;
}