10000的阶乘

#include <stdio.h>#define FACTORIAL_NUM 10000 /*阶乘数*/#define CONVERSION_VALUE 10000 /*虚拟进制位, 必须比阶数大且是10次方*/#define RESULT_ARR_LEN 8192 /*阶乘结果数组的长度*/void factorial(){static int nArr[RESULT_ARR_LEN] = {0}; /*保存结果的数组,不可以使用局部变量*/int nTemp = 0; /*临时变量*/int nFactorial = 0; /*当前阶乘数*/int nIndex = 0; /*数组索引*/int nFlag = 0; /*是否增大数组索引标识位*/int nCnt = 1; /*当前数组索引最大值*//*将结果初值置为1*/nArr[0] = 1;/*省略阶乘1, 因为任何乘1得任何数*/for (nFactorial = FACTORIAL_NUM; nFactorial > 1; nFactorial--){nFlag = 0;for(nIndex = 0; nIndex < nCnt; nIndex++){nTemp = nArr[nIndex] * nFactorial + nFlag;nArr[nIndex] = nTemp % CONVERSION_VALUE;nFlag = nTemp / CONVERSION_VALUE;}nArr[nIndex] = nFlag;if (nFlag > 0){nCnt++;}}/*输出计算结果*/printf("%d", nArr[nCnt-1]);for(nIndex = nCnt - 2; nIndex >= 0; nIndex--){/*这里的4, 必须是虚拟进制位的0的个数*/printf("%04d", nArr[nIndex]);}printf("/n");}