压缩字符串

Objective-c

/*
//压缩字符串
//比如输入@"aaabbbcceaa" 输出@"3a3b2c1e2a"
+(NSString*)compString:(NSString*)srcStr;

*/

//我的思路
//1.循环取出字符串中得字母，进行比较，如果相同就计数加一
//注意：
//[ str2 appendFormat:@"%d%c",count,a];必须放到else里面
//如果没有
/*f (i == length-2) {
            [ str2 appendFormat:@"%d%c",count,a];
        }
*/
//程序不会取到最后两个字符，会卡在count++里面
int main()
{
    NSString *str1 = @"aaabbbcceaa";
    char a,b;
    int count = 1;
    NSInteger length = [str1 length];
    NSLog(@"length = %ld",length);
    NSMutableString *str2 = [NSMutableString string];
    for (NSInteger i=0; i<length-1; i++) {
        a = [str1 characterAtIndex:i];
        b = [str1 characterAtIndex:i+1];
        if (a==b) {
            count++;
        }
        else
        {
           [ str2 appendFormat:@"%d%c",count,a];
          count = 1;
        }
        if (i == length-2) {
            [ str2 appendFormat:@"%d%c",count,a];
        }
    }
    NSLog(@"str2---->%@",str2);
}