2367. 算术三元组的数目c

int count;

void dfs(int* nums,int numsSize,int diff,int index,int pre,int nowcount){
    if(index>numsSize || nowcount>3) return;
    if(index==numsSize && nowcount<3) return;
    if(nowcount==3){
        count++;
        return;
    }
    if(  nowcount==0 || nums[index]==diff+pre ){
        dfs(nums,numsSize,diff,index+1,nums[index],nowcount+1);
        dfs(nums,numsSize,diff,index+1,pre,nowcount);
    }else{
        dfs(nums,numsSize,diff,index+1,pre,nowcount);
    }
}

int arithmeticTriplets(int* nums, int numsSize, int diff) {
    count=0;
    dfs(nums,numsSize,diff,0,0,0);
    return count;
}