大数加法.减法.乘法.除法

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大数加法

代码实现：

#include <stdio.h>#include <string.h>typedef char Str[1000];void PrintNum(int sum[] , int len)///---------输出{        int i;        for(i = len-1 ; i >= 0 ; i--)                printf("%d",sum[i]);        printf("\n");}void Add(Str a , int len_a , Str b , int len_b)///-----计算a+b(只能：+){        int k = 0 , c = 0;        int max_len = len_a > len_b ? len_a : len_b;        int sum[max_len+2];        for( ; len_b >= 0 ; ){///---a+b                sum[k++] = (a[len_a--]+b[len_b--]-96+c)%10;                c = (a[len_a+1]+b[len_b+1]-96+c) > 9 ? 1 : 0;        }        while(len_a > -1){///-----复制a                sum[k++] = (a[len_a]-48+c)%10;                c = (a[len_a]-48+c) > 9 ? 1 : 0;                len_a--;        }        if(c > 0)                sum[k++] = 1;        PrintNum(sum , k);}int main()///-------main(){        Str a , b;        while(~scanf("%s %s", a , b)){                int len_a = strlen(a);                int len_b = strlen(b);                if(len_a >= len_b)                        Add(a , len_a-1 ,  b ,  len_b-1);                else                        Add(b , len_b-1 ,  a ,  len_a-1);        }        return 0;}

大数减法

代码实现

#include <stdio.h>#include <string.h>typedef char Str[1000];void PrintNum(int sum[] , int len , char CH)///----输出{        int i;        if(CH == '-')                printf("%c",CH);        for(i = len-1 ; i >= 0 ; i--){                if(i == len-1 && sum[i] == 0){                        while(sum[i] == 0) i--;                }                printf("%d",sum[i]);        }        printf("\n");}void Sub(Str a , Str b , char CH)///-----计算a-b（a,b只能为：+）{        int len_a = strlen(a)-1;        int len_b = strlen(b)-1;        int sum[len_a+2];        int k = 0 , c = 0 , n = 0 , m = 0;        for( ; len_b >= 0 ; ){///-------计算a-b                m = a[len_a]-48 ; n = b[len_b]-48;                sum[k++] = (m-n-c) < 0 ? (10+m-n-c) : (m-n-c);                c = m >= (n+c) ? 0 : 1;                len_a-- ; len_b--;        }        while(len_a > -1){///------复制a                m = a[len_a]-48;                sum[k++] = (m-c) < 0 ? (10+m-c) : (m-c);                c = (m-c) >= 0 ? 0 : 1;                len_a--;        }        PrintNum(sum , k , CH);}int main()///-----main(){        Str a , b;        while(~scanf("%s %s",a , b)){///---多组输入                if(strcmp(a , b) > 0)                        Sub(a , b , '+');                else if((strcmp(a ,  b)) == 0)                        printf("0\n");                else                        Sub(b , a , '-');        }        return 0;}

大数乘法

代码实现

#include <stdio.h>#include <string.h>typedef char Str[1000];void PrintNum(int sum[] , int len)///-------输出{        int i;        for(i = len-1 ; i >= 0 ; i--){                if(i == len-1 && sum[i] == 0){                        while(sum[i] == 0) i--;                }                printf("%d",sum[i]);        }        printf("\n");}void Mul(Str a , int len_a , Str b , int len_b)///--------计算乘积a*b(只能：+){        int i , j , k , c;        int len = len_a*len_b;        int sum[len];        memset(sum , 0 , sizeof(sum));        for(i = len_b-1 ; i >= 0 ; i--){                c = 0 ; j = len_b-i-1;                for(k = len_a-1 ; k >= 0 ; k--){                       int s = (a[k]-48)*(b[i]-48)+c;                       c = (s+sum[j])/10;                       sum[j++] = (sum[j]+s)%10;                }                if(c > 0){                        sum[j] = (sum[j]+c)%10;                }        }        PrintNum(sum , len);}int main()///-----main(){        Str a , b;        while(~scanf("%s %s",a,b)){                if(a[0] == '0' || b[0] == '0'){                        printf("0\n");                        continue;                }                if(strlen(a) >= strlen(b))                        Mul(a , strlen(a) , b , strlen(b));                else{                        Mul(b , strlen(b) , a , strlen(a));                }        }        return 0;}

大数除法

#include <stdio.h>#include <string.h>#include <stdlib.h>typedef char Str[1000];void PrintNum(char sum[]){///---print        int i;        for(i = 0 ; i < strlen(sum) ; i++){                if(i == 0 && sum[i] == '0')                        while(sum[i] == '0') i++;                printf("%c",sum[i]);        }        printf("\n");}void Div(Str a , Str b)///-------div a/b{        Str sum;        int len_a = strlen(a);        int len_b = strlen(b);        char str[len_b+2];        int i , j = 0 , k = 0 , tem_i , num , temp = 0;        for(i = 0 ; i < len_a ; i++){                str[j++] = a[i] ; num = 0;                if((temp == 0 || temp == 1 && j == len_b) || (j > len_b)){                        str[j] = '\0' ; temp = 1;                        if(strcmp(str , b) < 0 && strlen(str) == len_b){                                sum[k++] = num+'0';                                continue;                        }                        while((strcmp(str , b) >= 0 && strlen(str) == len_b) || strlen(str) > len_b){                                int c = 0;                                for( tem_i = len_b-1 , j -= 1; tem_i >= 0 ; tem_i-- , j--){///-------str-b                                        int m = str[j]-48 ; int n = b[tem_i]-48;                                        str[j] = (m-n-c) < 0 ? (10+m-n-c)+'0' : (m-n-c)+'0';                                        c = m >= (n+c) ? 0 : 1;                                }                                str[j] = str[j]-48-c+'0';                                num++ ; j = 0;                                for(tem_i = 0 ; tem_i < strlen(str) ; tem_i++){                                        if(tem_i == 0 && str[tem_i] == '0')                                                while(str[tem_i] == '0') tem_i++;                                        if(tem_i < strlen(str))                                                str[j++] = str[tem_i];                                }                                str[j] = '\0';                        }                        sum[k++] = num+'0';                }                else if(j < len_b && temp == 1){                         sum[k++] = '0';                         if(str[0] == '0') j = 0;                }        }        sum[k] = '\0';        PrintNum(sum);}int main()///--main(){        int m;        Str a , b;        scanf("%d",&m);        while(m--){                scanf("%s %s",a,b);                if(a[0] == '0' || b[0] == '0' || strlen(a) < strlen(b)){                        printf("0\n");                        continue;                }                if(strcmp(a , b) < 0 && strlen(a) == strlen(b)){                        printf("0\n");                        continue;                }                if(strcmp(a , b) == 0){                        printf("1\n");                        continue;                }                Div(a,b);        }        return 0;}