XDOJ_695_等差数列及位置指示

#include <stdio.h>
#include <stdlib.h>//为qsort提供头文件

int compare(const void *a, const void *b) {
    return (*(int *)a - *(int *)b);
}

void find(int arr[], int size, int *maxDifference, int *minDifference) {//找出最大差值和最小差值的函数
    *maxDifference = arr[1] - arr[0];
    *minDifference = arr[1] - arr[0];

    for (int i = 1; i <= size - 1; i++) {
        int diff = arr[i] - arr[i - 1];
        if (diff > *maxDifference) {
            *maxDifference = diff;
        }
        if (diff < *minDifference) {
            *minDifference = diff;
        }
    }
}

int main() {
    int n;
    scanf("%d", &n);
    int arr1[n], arr2[n];//arr2是arr1的副本，用于后续比较
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr1[i]);
    }
    for(int i = 0; i < n; i++){
        arr2[i] = arr1[i];
    }

    qsort(arr1, n, sizeof(int), compare);//递增排序arr1的快速函数

    int diff = arr1[1] - arr1[0];
    int isArithmetic = 1;//标记

    for (int i = 2; i < n; i++) {
        if (arr1[i] - arr1[i - 1] != diff) {
            isArithmetic = 0;
            break;
        }
    }
    int max, min;

    if(isArithmetic){
        for(int i = 0; i < n; i++){
            for(int j = 0; j < n; j++){
                if(arr1[i] == arr2[j]){
                    printf("%d ", j + 1);
                }
            }
        }
    }else{
        find(arr1, n, &max, &min);//调用求最大差值和最小差值的函数
        printf("%d %d", max, min);
    }

    return 0;
}