iOS 判断用户设置密码是否太简单（如 123，456，111）

- (BOOL)validateLianxu:(NSString *)passWord{

NSString *last = @"";

int sub = -1;

for (int i = 0; i< passWord.length; i++) {

NSString *str = [passWord substringWithRange:NSMakeRange(i, 1)];

if ([last isEqualToString:@""]) {

//第一次进来

last = str;

continue;

}

if (sub == -1) {

//第二次进来

sub = str.integerValue - last.integerValue;

if (sub>1 ||sub <-1) {

return NO;

}

last = str;

continue;

}

int current_sub = str.integerValue - last.integerValue;

if (current_sub != sub) {

return NO;

}

last = str;

}

return YES;

}