[pascalTriangle.II] mistakes

In code
```
for (int i=0; i<rowIndex; i++){
        for(int j=i+1; j>0; j--){
           v[j] += v[j-1];
        } 
    }
```
when `i` equals `rowIndex-1` and `j` equals `rowIndex`, the `v` doesn't have the element at `j`.