如何同时使用两个malloc函数
例如这里为啥不行呢！
#include <stdio.h>
#include <stdlib.h>
void ReadScore(long *pn,float *ps,int n,int m);
void PrintScore(long *pn,float *ps,int n,int m);
int main()
{
    int n, m, choice;
    long num[30];
    float score[100];
    long *ps = num;
    float *pn = score;
    printf("Please input the number of students:");
    scanf("%d", &n);
    printf("Please input the number of couses:");
    scanf("%d", &m);
    ps = (int*)malloc(n*sizeof(int));
    pn = (float*)malloc(n*m, sizeof(float));
    if(ps == NULL || pn == NULL)
    {
        exit(1);
    }
    ReadScore(pn,ps,n,m);
    return 0;
}

void ReadScore(long *pn,float *ps,int n,int m)
{
    int i;
    for(i = 0; i<n; i++)
    {
        printf("Input num and score :");
        scanf("%ld%f",&pn[i]);
        for(j = 0; j < m; j++)
        {
            scanf("%f", &ps(i*n+j));
        }
        printf("\n");
    }
}

错误显示就是这样的