public class CountingSort {
    int[] sort() {
        int N = 10000;
        int M = 100;//假设A中最大值为100
        int A[] = new int[N];//1~k,原数组
        int B[] = new int[N];//1~k,Stores incompletely sorted numbers
        int C[] = new int[M + 1];//0~n,辅助排序数组
        for (int i = 0; i <= M; i++) {
            C[i] = 0;
        }
        for (int i = 0; i < A.length; i++) {
            C[A[i]] += 1;
        }
        //统计<=i的个数
        for (int i = 0; i <= M; i++) {
            C[i] = C[i] + C[i - 1];
        }
        for (int i = N; i >= 1; i--) {
            B[C[A[i]]] = A[i];
            C[A[i]] -= 1;
        }
        return B;
    }

}

C告诉B应该把A排在哪里，每排一个数字，都要把相应<=的个数减1