////  main.m//  字符串逆序////  Created by syrcfwzx on 16/1/9.//  Copyright (c) 2016年 syrcfwzx. All rights reserved.//#import 
     
      int main(int argc, const char * argv[]) {    @autoreleasepool {//        2.将字符串按照单词逆序 (10分)//        //        输入一段字符串，已知字符串只由字母和空格构成，将字符串按照单词逆序//        //        传入@"welcome to qianfeng"//        //        返回 @"qianfeng to welcome"        NSString* str = @"welcome to qianfeng";//        NSMutableString* reverse = [NSMutableString string];//        NSInteger len = [str length];//        for(NSInteger i =len-1 ;i>0;i--)//        {//            unichar c =[str characterAtIndex:i];//            NSString* temp = [NSString stringWithCharacters:&c length:1];//            [reverse appendString:temp];//            //        }//        NSLog(@"%@",reverse);//        NSArray* array = [str componentsSeparatedByString:@" "];        NSMutableArray* arr = [NSMutableArray array];                for(NSInteger i=[array count]-1;i>=0;i--)        {            [arr addObject:array[i]];        }            NSString* newstr = [arr componentsJoinedByString:@" "];        NSLog(@"%@",newstr);            }    return 0;}