Algorithm-Large integer addition

Note Here is an integer, floating-point numbers need extra operations, to achieve the addition and subtraction of large integers, three stacks ok, two arithmetic integer stack, a result stack, the basic logic is the use of the first-in-one stack of the characteristics of the top push to the bottom of the stack, low push to the stack, and then push to the result stack after two , the result stack pops out is the result we want. Look good, if you are interested in the following code, code through OC Implementation, the principle is similar:

Since OC does not have a stack, it is easy to implement a stack first:

Stack.h:

Element @property  (strong,nonatomic) Node *first @interface stack:nsobject//stack top,  @property  (assign,nonatomic ) Nsinteger  count;-(BOOL) isempty;-(Nsinteger) size;-(void) Push: (NSString *) value;-(NSString *) pop;-(void) Remove: (NSString *) value; @end

STACK.M Code:

@implementation stack-(BOOL) isempty{return self.count==0;} -(Nsinteger) size{return self.count;}    -(void) Push: (NSString *) value{Node *oldfirst=self.first;    Self.first=[[node Alloc]init];    Self.first.value=value;    Self.first.next=oldfirst; self.count=self.count+1;}    -(NSString *) pop{if (!self.first) {return [NSString stringwithformat:@ "-1"];    } NSString *value=self.first.value;    Self.first=self.first.next;    self.count=self.count-1; return value;}        -(void) Remove: (NSString *) value{if ([Self.first.value Isequaltostring:value]) {self.first=self.first.next;    self.count=self.count-1;        }else{Node *node=self.first;                    while (Node.next) {if ([Node.next.value Isequaltostring:value]) {if (Node.next.next) {                    Node *tempnode=node.next.next;                Node.next=tempnode;                }else{Node.next=null; } self.count=self.count-1;            Break            }else{Node=node.next; }}} @end

into focus, the addition and subtraction of integers is implemented in StackSum.h:

@interface stacksum:nsobject-(Nsinteger) sum: (Nsinteger) Firstnumber  secondnumber: (Nsinteger) secondnumber;@ End

Code in STACKSUM.M:

@implementation stacksum//Original address: http://www.cnblogs.com/xiaofeixiang-(nsinteger) sum: (Nsinteger) Firstnumber    Secondnumber: (Nsinteger) secondnumber{//stack stack for the first integer *firststack=[self Getstackbynumber:firstnumber];    Stack stack of the second integer *secondstack=[self Getstackbynumber:secondnumber];    Result Stack stack *resultstack=[[stack alloc]init]; Nsinteger flag=0;//carry Tag while (firststack.count>0&&secondstack.count>0) {Nsinteger Temp=[fi        Rststack.pop Integervalue]+[secondstack.pop Integervalue]+flag;        [Resultstack push:[nsstring stringwithformat:@ "%ld", temp%10]];    FLAG=TEMP/10;        }//The first number is greater than the number of the second word while (firststack.count>0) {Nsinteger temp=[firststack.pop integervalue]+flag;        [Resultstack push:[nsstring stringwithformat:@ "%ld", temp%10]];    FLAG=TEMP/10;        }//The second number is greater than the first number while (secondstack.count>0) {Nsinteger temp=[secondstack.pop integervalue]+flag; [Resultstack push:[nsstring Stringwithformat:@ "%ld", temp%10]];    FLAG=TEMP/10;    }//Mark Bit has carry if (flag) {[Resultstack push:[nsstring stringwithformat:@ "%ld", Flag]];    } Nsinteger Count=resultstack.count;    NSString *[email protected] "";   The positive sequence output is the result for (Nsinteger i=0; i<count; i++) {str=[str StringByAppendingString:resultStack.pop]; } return [str integervalue];}    -(Stack *) Getstackbynumber: (nsinteger) value{Stack *stack=[[stack Alloc]init];    NSString *stringvalue=[nsstring stringwithformat:@ "%ld", value]; for (Nsinteger i=0; i<[stringvalue length]; i++) {[Stack push:[nsstring stringwithformat:@ '%@ ', [stringvalue su    Bstringwithrange:nsmakerange (i, 1)]]; } return stack; @end

A simple test:

    Stacksum  *sum=[[stacksum Alloc]init];    NSLog (@ "Large integers add the result:%ld", [sum sum:9999999 secondnumber:888]);    NSLog (@ "iOS technology Group: 228407086");

The results are as follows:

Randomly attached iOS technology group: 228407086~

Algorithm-Large integer addition