c - C 中的双数组打印输出给了我奇怪的输出

Question

     a = (float**)malloc(num * sizeof(float*));
     if( !a)  {
     printf("Cannot allocate a!\n");
     exit(1);
     }

     for(i = 0; i < num; i++) {
     a[i] = (float *)malloc(num * sizeof(float));
     if( !a[i]) {
            printf("Cannot allocate a[%d]!\n",i);
            exit(1);
     }}

    for(i = 0; i < num; i++) {
        for(j = 0; j < num; j++)
            fscanf(fp,"%f ",&a[i][j]);
    }


    // in a method called after a is initialized and elements are recorded. 
    int s, t;
    printf("This is num: %d\n", num);
    for (s = 0; s < num; s++) {

            for (t = 0; t < num; t++) {
                    printf("This is a[s][t]:%d for s:%d and t:%d\n", a[s][t], s, t);
            }
    }

This is num: 3 This is a[s][t]:0 for s:0 and t:4198765 This is a[s][t]:0 for s:1 and t:4199061 This is a[s][t]:0 for s:2 and t:4199061 This is a[s][t]:1 for s:0 and t:4199061 This is a[s][t]:1 for s:1 and t:4199061 This is a[s][t]:1 for s:2 and t:4199061 This is a[s][t]:2 for s:0 and t:4199061 This is a[s][t]:2 for s:1 and t:4199061 This is a[s][t]:2 for s:2 and t:4199061

//这是矩阵输入5 1 3 63 7 2 83 6 9 6

//顺序不对!

Answer 1

您应该使用 %f 来打印 float ，并检查每个 fscanf 是否成功或失败。