give array num we define run sum array runningsumi sumnums0numsireturn run sum num Example 1input num 1234output 13610explanation running sum obtain follow 1 12 123 1234example 2input num 11111output 12345explanation running sum obtain follow 1 11 111 1111 11111example 3input num 312101output 3461617 Constraints1 numslength 1000106 numsi 106