Added solution to string reverse
Added solution to string reverse

smac89/playground,smac89/playground,smac89/UVA_OJ,smac89/playground,smac89/UVA_OJ,smac89/UVA_OJ,smac89/playground,smac89/UVA_OJ,smac89/playground,smac89/UVA_OJ,smac89/UVA_OJ,smac89/playground