50129. Loops

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include "loops.h"

#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))

static int vis[1000005] = {0};


int next_idx(int* a, int *b[], int idx){
    return (b[idx] - a);
}

static int max_num;
static int min_num;
static int len;
void traverse(int *a, int *b[], int idx){
    max_num = INT_MIN, min_num = INT_MAX, len = 0;
    while(!vis[idx]){
        vis[idx] = 1;
        max_num = max(max_num, a[idx]);
        min_num = min(min_num, a[idx]);
        len++;
        idx = next_idx(a, b, idx);
    }
}

void loops(int n, int *a, int *b[], int ans[4]){
    for(int i = 0; i < n; i++) vis[i] = 0;

    int min_len = INT_MAX;
    int min_el = INT_MAX;
    int max_len = INT_MIN;
    int max_el = INT_MIN;
    for(int i = 0; i < n; i++){
        if(vis[i]) continue;
        traverse(a, b, i);

        if(len < min_len){
            min_el = min_num;
            min_len = len;
        }
        else if(len == min_len){
            min_el = min(min_el, min_num);
        }

        if(len > max_len){
            max_el = max_num;
            max_len = len;
        }
        else if(len == max_len){
            max_el = max(max_el, max_num);
        }
    }
    ans[0] = max_len;
    ans[1] = min_len;
    ans[2] = max_el;
    ans[3] = min_el;
}