From 20115d9183f6fb7a15cb106a3d698070eb54c3ea Mon Sep 17 00:00:00 2001
From: Jourdain Marine <telect@telect-laptop.(none)>
Date: Sun, 7 Dec 2008 15:22:24 +0100
Subject: [PATCH] *sumBigInt implementation 2

---
 biginteger.c | 119 +++++++++++++++++++++++++++++++++++++++++------------------
 biginteger.h |   2 +-
 2 files changed, 85 insertions(+), 36 deletions(-)

diff --git a/biginteger.c b/biginteger.c
index cc898ea..4b0c51c 100644
--- a/biginteger.c
+++ b/biginteger.c
@@ -115,23 +115,30 @@ void InsertNode(BigInteger* bigInt, BigUnsignedInteger* next, unsigned int value
 
 BigInteger newBigInteger(char* desc)
 {
-  BigInteger newbigint=CreateZeroBigInt();
-  int i;//iterative variable
-  char temp[5];//array of character where islu
-  unsigned int tempint;//temporary variable where is stored the integer incoming from the transformation 'character to interger'
-
-  for(i=strlen(desc)-5;i>=0;i=i-4){//loop to build the double linked list until we reach the last group of 4 characters
-	strncpy(temp,desc + i,4);
-	temp[5]='\0';
-	tempint=atoi(temp);
-	PushEndNode(&newbigint,tempint);
+  BigInteger   newbigint=CreateZeroBigInt();
+  //iterative variable
+  int          i;
+  //array of character where is stored a part of the total list of character
+  char         temp[5];
+  //temporary variable where is stored the integer incoming from the transformation 'character to interger'
+  unsigned int tempint;
+  
+  //loop to build the double linked list until we reach the last group of 4 characters
+  for(i = strlen(desc)-5; i >= 0; i = i - 4) {
+	  strncpy(temp, desc + i,4);
+	  temp[5] = '\0';
+	  tempint = atoi(temp);
+	  PushEndNode(&newbigint,tempint);
   }
-  if(i<0){//test if the number of digit of the number is divisible by 4. if it's not the case, it completes with the rest
-	strncpy(temp,desc,i+4);
-	temp[i+5]='\0';
-	tempint=atoi(temp);
-	PushEndNode(&newbigint,tempint);
+  
+  //test if the number of digit of the number is divisible by 4. if it's not the case, it completes with the rest
+  if (i < 0) {
+	  strncpy(temp, desc, i + 4);
+	  temp[i+5] = '\0';
+	  tempint = atoi(temp);
+	  PushEndNode(&newbigint, tempint);
   }
+  
   return newbigint;
 }
 
@@ -142,50 +149,92 @@ void printBigInteger(BigInteger bint)
 
 Boolean isNull(BigInteger bint)
 {
-
+  return false;
 }
 
 int signBigInt(BigInteger bint)
 {
-
+  return -1;
 }
 
 Boolean equalsBigInt(BigInteger b1, BigInteger b2)
 {
-
+  return false;
 }
 
 int compareBigInt(BigInteger b1, BigInteger b2)
-{
-  
+{ 
+
 }
 
 BigInteger sumBigInt(BigInteger b1, BigInteger b2)
 {
-  BigInterger Sum=CreateZeroBigInt();//variable which will be the result of the sum
-  BigInteger p1=b1;//temporary pointer  over b1
-  BigInterger p2=b2;//temporary pointer over b2
-  int carry=0;//the carry can be equal to 0 or 1
-  while(p1!=NULL && p2!=NULL){//do the addition until we reach the last node of one of the two numbers, or both
-    PushFrontNode(&Sum, (p1->value + p2->value + carry)%10000);
-    if(p1->value + p2->value>=10000)//compute the carry
+  //test if b2 is negative
+  if(b1.Sign==Positive && b2.Sign==Negative){
+    b2.Sign=Positive;
+    return diffBigInt(b1,b2);
+  }else{
+    //test if b1 is negative
+    if(b1.Sign==Negative && b2.Sign==Positive){
+      b1.Sign=Positive;
+      return diffBigInt(b2,b1);
+    }
+  }
+  //variable which will be the result of the sum
+  BigInteger Sum = CreateZeroBigInt();
+  //temporary pointer  over b1
+  BigUnsignedInteger* p1 = b1.AbsValStart;
+  //temporary pointer over b2
+  BigUnsignedInteger* p2 = b2.AbsValStart;
+  //test if the two BigInteger are null
+  
+  if (b1.Sign == Undefined && b2.Sign == Undefined){
+    return Sum;
+  }else{
+    //test if one of the 2 BigInt is null
+    if (b1.Sign == Undefined && b2.Sign != Undefined)
+      Sum = b2;
+    else if (b2.Sign == Undefined && b1.Sign != Undefined)
+        Sum = b1;
+    
+  }
+  
+  //test if the 2 BigInt are both positive or both negative
+  int carry=0;
+  //do the addition until we reach the last node of one of the two numbers, or both
+  while(p1 != NULL || p2 != NULL){
+    unsigned int s=(p1==NULL ? 0 : p1->Value) + (p2==NULL ? 0 : p2->Value) + carry;
+    PushEndNode(&Sum, s%10000);
+    //compute the carry
+    if(s >= 10000)
+      //if the sum exceed 10000
       carry=1;
     else
       carry=0;
-  p1=p1->next;
-  p2=p2->next;    
-  }  
-  if(p1==NULL && p2!=NULL)
-    PushFrontNode(&Sum,p2->value);
-  else{
-    if(p2==NULL && p1!=NULL)
-      PushFrontNode(&Sum,p1->value);  
+    
+    if (p1 == NULL) {//test if p2 is longer than p1
+      p2=p2->Next;
+    }else if (p2==NULL) { //test if p1 is longer than p2
+      p1=p1->Next;
+    }   
   }
+  if(carry==1){
+    PushEndNode(&Sum,1);
+  }
+  //if the two numbers are both negative
+  if(b1.Sign == Negative && b2.Sign == Negative)
+      Sum.Sign=Negative;
+ 
+  return Sum;
 }
 
 BigInteger diffBigInt(BigInteger b1, BigInteger b2)
 {
 
+
+
+
+  return CreateZeroBigInt();
 }
 
 // End Public Function Impl
diff --git a/biginteger.h b/biginteger.h
index e729429..b053bd8 100644
--- a/biginteger.h
+++ b/biginteger.h
@@ -51,7 +51,7 @@ typedef struct {
   // The absolute value which is multiplied by sign to get the real integer value
   BigUnsignedInteger* AbsValStart; // Head
   BigUnsignedInteger* AbsValEnd; // Tail
-
+  int Count;
 } BigInteger;
 
 
-- 
2.11.4.GIT