HJ3 明明的随机数 HJ03

​​HJ3 明明的随机数​​

输入的数字大小满足 1≤val≤500, 因为数据范围小而且都是整数，val作为数组下标，数组值记录出现次数，顺序输出值>0的数组下标即可。😄

#include <iostream>

int main() {
    int valArr[500] = {0};
    int num = 0;
    int n = 0;
    
    std::cin >> n;
    while (n-- > 0) {
        std::cin >> num;
        valArr[num] += 1;
    }
    int sz = sizeof(valArr)/sizeof(valArr[0]);
    for (int i = 0; i < sz; i++) {
        if (valArr[i] > 0) {
            std::cout << i << std::endl;
        }
    }
 
    return 0;
}

用快速排序:

#include <iostream>

template <typename T>
class HJ03 {
private:
    static T partition(T arr[], int low, int high) {
        T pivot = arr[low];
        while (low < high) {
            while (low < high && arr[high] >= pivot) {
                --high;
            }
            arr[low] = arr[high];
            while (low < high && arr[low] <= pivot) {
                ++low;
            }
            arr[high] = arr[low];
        }
        arr[low] = pivot;
        return low;
    }
public:
    void qsort(T arr[], int low, int high) {
        if (low >= high) {
            return;
        }
        int pivotIndex = partition(arr, low, high);
        qsort(arr, low, pivotIndex-1);
        qsort(arr, pivotIndex+1, high);
    }
};

int main() {
    HJ03<int> q;
    int arrIn[1000] = {0};
    int arrOut[1000] = {0};
    int n = 0, i = 0;

    std::cin >> n;
    if (n < 1) {
        return 0;
    }
    for (; i < n; i++) {
        std::cin >> arrIn[i];
    }
//    n = 4;
//    arrIn[0] = 2;
//    arrIn[1] = 2;
//    arrIn[2] = 3;
//    arrIn[3] = 1;
    q.qsort(arrIn, 0, n-1);
    // for (i = 0; i < n; i++) {std::cout << arrIn[i] << std::endl;}

    arrOut[0] = arrIn[0];
    int j = 0;
    for (i = 1; i < n; i++) {
        if (arrIn[i] != arrOut[j]) {
            arrOut[++j] = arrIn[i];
        }
    }
    int m = j+1;
    // std::cout << "m=" << m << "\n";
    for (j = 0; j < m; j++) {
        std::cout << arrOut[j] << std::endl;
    }

    return 0;
}