public class NumArray {

```
int[] nums;
public NumArray(int[] nums) {
for(int i = 1; i < nums.length; i++)
nums[i] += nums[i - 1];
this.nums = nums;
}
public int sumRange(int i, int j) {
if(i == 0)
return nums[j];
return nums[j] - nums[i - 1];
}
```

}