I have a tensor A with shape of (32,200,50,2), and tensor B with shape of (32,100,100,128).

Tensor A is integer tensor. The lower bound of tensor A is 0 and upper bound of tensorA is 99. Therefore tensor A can be used as index tensor for tensor B.

From tensor A and tensor B, I want to generate tensor C with shape of (32,200,50,128).

The code for get tensor C is below.

```
C=torch.zeros(*A.shape[:-1], B.shape[-1])
for b in range( A.shape[0]):
for i in range(A.shape[1]):
for j in range(A.shape[2]):
C[b, i, j, :]= B[b, A[b,i,j,0], A[b,i,j,1], :]
```

How can I do the same job without using ugly for loop?