博客

//大数除法运算

+(NSArray *)exceptActionString:(NSString *)string1 andString:(NSString *)type{

NSMutableArray *numberArray = [[NSMutableArray alloc] init];

//整除
NSInteger number;
NSString *str1;
NSInteger remainder = 0;

//判断除数的长度是否比被除数长
if(string1.length >= type.length){
    
    for(int i = 0; i < string1.length - (type.length -1);i++){
        
        if (i > 0) {
            
            //取出下一次运算的数据
            str1 = [string1 substringWithRange:NSMakeRange(i + type.length -1,1)];
            
            if (remainder != 0) {
                //把余数 和 下一次运算的数据取出 组成新的除数
                str1 = [NSString stringWithFormat:@"%ld%@",(long)remainder,str1];
            }
            
        }else{
            //取出第一次运算的除数
            str1 = [string1 substringWithRange:NSMakeRange(i, type.length)];
        }
        
        //整除
        number = [str1 integerValue]/[type integerValue];
        
        //取余
        remainder = [str1 integerValue]%[type integerValue];
        
        [numberArray insertObject:[NSString stringWithFormat:@"%ld",(long)number] atIndex:i];
    }
    
    //去掉无效的0
    if (numberArray.count > 0) {

        NSInteger i = 0;
        
        while (i < numberArray.count -1) {
            
            NSString *str1 = numberArray[0];
            
            if ([str1 integerValue] == 0) {
                //去掉无效的0
                [numberArray removeObjectAtIndex:i];
            }else{
                break;
            }
            i++;
        }
    }
    
    NSString *string = [numberArray componentsJoinedByString:@""];
    
    NSArray *arr = @[string,[NSString stringWithFormat:@"%ld",(long)remainder]];
    return arr;
    
}else{
    
    return @[@"运算错误"];
}

}

注：返回的数据类型为数组，存放计算结果和余数