30:00
Merge nums2 into nums1 as one sorted array. nums1 has enough space (size m + n) to hold additional elements from nums2.
nums1.length==m+n\text{nums}_1.\text{length} == m + nnums1.length==m+n
nums2.length==n\text{nums}_2.\text{length} == nnums2.length==n
0≤m,n≤2000 \leq m, n \leq 2000≤m,n≤200
1≤m+n≤2001 \leq m + n \leq 2001≤m+n≤200
−109≤nums1[i],nums2[i]≤109-10^9 \leq \text{nums}_1[i], \text{nums}_2[i] \leq 10^9−109≤nums1[i],nums2[i]≤109
Merge from the end