定义的时候变量的位置就是最后一个星号的位置

int*** matrix3d_int(int nz, int nrh, int nch) {int*** matrix = (int***)malloc(nz * sizeof(int**));for (int z = 0; z < nz; z++) {matrix[z] = (int**)malloc(nrh * sizeof(int*));for (int y = 0; y < nrh; y++) {matrix[z][y] = (int*)malloc(nch * sizeof(int));}}return matrix;
}