c语言为正数无限大,无限大整数相加算法的C语言源代码

#include #include#include#include

#define MAXNUM 1000000000000000000

/*存储数据用的结构

long int型指针(Number)指向一个long int 数组，索引值最底的位，

为10进制数的最低18位。依次类推。

int型数值(Length)为数组的长度。

因为数组长度受int型最大值的限制，所以这个算法也不能真正实现“无限”。*/

structBigInt{long long*Number;intLength;

};void PrintBigInt(BigInt*bigNumber);long long pow(int x, inty);

BigInt* MakeBigIntFromString(char*bigIntString);void DeleteBigInt(BigInt*bigNumber);

BigInt* Add2BigInt(BigInt* n1, BigInt*n2);voidmain(){char* numberStr = "99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999";char* numberStr2 = "99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999";

BigInt* bn =MakeBigIntFromString(numberStr);

BigInt* bn2 =MakeBigIntFromString(numberStr2);doubletstart, tend, tcost;

tstart=clock();

PrintBigInt(bn);

PrintBigInt(bn2);for (int i = 0; i < 1000; i++){

BigInt* result =Add2BigInt(bn, bn2);//PrintBigInt(result);

DeleteBigInt(result);

}

DeleteBigInt(bn);

DeleteBigInt(bn2);

tend=clock();

tcost= (double)(tend - tstart) /CLOCKS_PER_SEC;

printf("%lfn", tcost);

}

BigInt* Add2BigInt(BigInt* n1, BigInt*n2){int maxLength = n1->Length;if (maxLength < n2->Length){

maxLength= n2->Length;

}/*加法只可能产生1位的进位，所以，只需要创建一个和最大长度相同的。*/BigInt* nOut = (BigInt*)malloc(sizeof(BigInt));

nOut->Length =maxLength;

nOut->Number = (long long*)malloc(sizeof(long long)* nOut->Length);for (int i = 0; i < nOut->Length; i++){

nOut->Number[i] = 0;

}for (int i = 0; i < nOut->Length; i++){if (n1->Length >i){

nOut->Number[i] += n1->Number[i];

}if (n2->Length >i){

nOut->Number[i] += n2->Number[i];

}/*处理进位。最高位不需要处理。*/

if (i != (nOut->Length - 1)){if (nOut->Number[i] >=MAXNUM){

nOut->Number[i] -=MAXNUM;

nOut->Number[i + 1] = 1;

}

}

}returnnOut;

}/*从高到低显示数值

不考虑单个long long数据超出18位的情况。*/

void PrintBigInt(BigInt*bigNumber){if (bigNumber ==NULL){return;

}if (bigNumber->Length < 1){return;

}int length = bigNumber->Length - 1;for (int i = length; i >= 0; i--){if (i !=length){if (bigNumber->Number[i] == 0){

printf("000000000000000000");

}else{

printf("%018lld", bigNumber->Number[i]);

}

}else{if ((*bigNumber).Number[i] != 0){

printf("%lld", bigNumber->Number[i]);

}

}

}

printf("n");

}/*把字符串表示的数值格式化为BigInt型的结构

字符串结束位置用表示。*/BigInt* MakeBigIntFromString(char*bigIntString){/*获取字符串长度*/

int cLength =strlen(bigIntString);

BigInt* outBigInt = (BigInt*)malloc(sizeof(BigInt));if (cLength % 18 != 0){

outBigInt->Length = cLength / 18 + 1;

}else{

outBigInt->Length = cLength / 18;

}if (outBigInt->Length == 0){

outBigInt->Length == 1;

outBigInt->Number = (long long *)malloc(sizeof(long long));

outBigInt->Number[0] = 0;returnoutBigInt;

}

outBigInt->Number = (long long *)malloc(sizeof(long long)* outBigInt->Length);for (int i = 0; i < outBigInt->Length; i++){

outBigInt->Number[i] = 0;

}int powNum = 0;int numPos = 0;for (int i = cLength - 1; i >= 0; i--){

powNum= (cLength - 1 - i) % 18;

numPos= (cLength - 1 - i) / 18;

outBigInt->Number[numPos] += (bigIntString[i] - 48) * pow(10, powNum);

}returnoutBigInt;

}/*简单的幂函数

x y 都必须为正整数*/

long long pow(int x, inty){if (x == 0 || x < 0 || y < 0){return 0;

}if (x == 1 || y == 0){return 1;

}long long outNum =x;for (int i = 1; i < y; i++){

outNum= outNum *x;

}returnoutNum;

}void DeleteBigInt(BigInt*bigNumber){if (bigNumber !=NULL){if (bigNumber->Number !=NULL){free(bigNumber->Number);

}free(bigNumber);

}

}