信息安全原理大数四则运算及DH算法C语言实现

// // main.c // InfoSe_hw2 // // Created by C-TEN on 2017/3/24. // Copyright © 2017年 C-TEN. All rights reserved. // #include <stdio.h> #include <string.h> #include <stdlib.h> //#define MAXINT 1000 char a[100],b[100]; int x[100],y[100],z[100],m[100]; int digit; void big_data_add(int a[],int b[],int c[],int lena,int lenb); void big_data_sub(int a[],int b[],int c[],int lena,int lenb); void big_data_multi(int a[],int b[],int c[],int lena,int lenb); void big_data_div(int a[],int b[],int lena,int lenb); int judge(int x[],int y[],int len1,int len2) { int i; if(len1<len2) return -1; else if(len1==len2) { for(i=len1-1;i>=0;i--) { if(x[i]==y[i]) continue; if(x[i]>y[i]) return 1; if(x[i]<y[i]) return -1; } return 0; } else return -1; } void sub(int x[],int y[],int len1,int len2) { int i; for(i=0;i<len1;i++) { if(x[i]<y[i]) { x[i]=x[i]+10-y[i]; x[i+1]--; } else x[i]=x[i]-y[i]; } for(i=len1-1;i>=0;i--) { if(x[i]) { digit=i+1; break; } } } int max(int a , int b){ if(a > b) return a; else return b; } int main(int argc, const char * argv[]) { int j,k,len,temp; printf("Input A operator B \n"); printf("for example 3672 / 213\n"); int A[1000]; char ch; int B[1000]; char tmp; int i = 0; while((tmp = getchar()) != ' ') A[i++] = tmp-'0'; int lena = i; ch = getchar(); getchar(); i = 0; while((tmp = getchar())>= '0' && tmp <= '9') B[i++] = tmp-'0'; int lenb = i; //getchar(); int result[1000]; switch(ch){ case'+': { big_data_add(A,B,result,lena, lenb); printf("The result is : \n"); i = 0; int lenr = max(lena, lenb); while(result[i]==0&&i<lenr) i++; for(;i<=lenr;i++){ printf("%d",result[i]); } printf("\n"); break; } case'-': { int flag = 0; if(lena < lenb) flag = 1;// a < b need reverse else if(lena == lenb){ i = 0; while(i<lena && A[i] <= B[i]){ if( A[i] < B[i] ) flag = 1; i++; } } if(flag){ printf("The result is : \n"); printf("-"); big_data_sub(B,A,result,lenb,lena); } else{ printf("The result is : \n"); big_data_sub(A,B,result,lena,lenb); } i = 1; int lenr = max(lena, lenb); while(result[i]==0&&i<lenr) i++; for(;i<=lenr;i++){ printf("%d",result[i]); } printf("\n"); break; } case'*':{ if(lena > lenb) big_data_multi(A,B,result,lena,lenb); else big_data_multi(B,A,result,lenb,lena); break; }//break; case'/':{ big_data_div(A,B,lena,lenb); //big_data_div(A,B,result,lena,lenb); break; } default : break; } //比较大小 // big_data_multi(A,B,result); // big_data_div(A,B,result); return 0; } void big_data_sub(int a[],int b[],int c[],int lena,int lenb){ int lenr = max(lena, lenb); int tmpa = a[lena-1]; int tmpb = b[lenb-1]; int i; int carry = 0; int tmpc = carry; //int flag = 0; for(i = lenr; i >= 0 ; i-- ) { tmpa = a[lena-1]; if(lenb-1<0) tmpb = 0; else tmpb = b[lenb-1]; tmpc = carry ; if(lena - 1 < 0 && lenb - 1 <0){ c[i] = tmpc; } else if(tmpa - tmpb - tmpc < 0){ c[i] = tmpa - tmpb - tmpc + 10; carry = 1; } else{ c[i] = tmpa - tmpb - tmpc; // printf("c[i] %d tmpa %d tmpb %d tmpc %d\n",c[i],tmpa,tmpb,tmpc); carry = 0; //break; } lena--; lenb--; } } void big_data_add(int a[],int b[],int c[],int lena ,int lenb){ int lenr = max(lena, lenb); //printf("%s\n", ); //printf("lena %d lenb %d\n",lena,lenb ); int tmpa = a[lena-1]; int tmpb = b[lenb-1]; int i; int carry = 0; int tmpc = carry; for(i = lenr; i >= 0 ; i-- ) { tmpa = a[lena-1]; tmpb = b[lenb-1]; tmpc = carry; if(lena - 1 < 0 && lenb - 1 <0){ c[i] = tmpc; } else if (lena-1 < 0) { c[i] = tmpb + tmpc; carry = 0; } else if (lenb - 1 < 0){ c[i] = tmpa + tmpc; carry = 0; } else if(tmpa + tmpb + tmpc> 9){ c[i] = tmpa + tmpb + tmpc - 10; carry = 1; } else{ c[i] = tmpa + tmpb + tmpc; carry = 0; } lena--; lenb--; } } void big_data_multi(int a[],int b[],int c[],int lena,int lenb){ int lenr = lena + lenb + 1; int tmpa = a[lena-1]; int tmpb = b[lenb-1]; int i; int rowc[lenr+1]; for(i = 0; i <= lenr;i++){ rowc[i] = 0; } int tmp; int carry = 0; int tmpc = carry; //calculate the first row int rowa[100]; int len = lena+1; int j = 0; int ai = len-1; int zero; for(i = lenb - 1 ; i >= 0 ; i--){ ai = len-1+lenb-1-i; zero = lenb-1-i; while(zero > 0){ // printf("zero %d \n", zero); // printf("%d \n", ai); rowa[ai--] = 0; zero--; } carry = 0; tmpb = b[i]; lena = len - 1; while(ai >= 0){ tmpa = a[lena-1]; tmpc = carry; tmp = tmpa*tmpb + tmpc; //printf("ai %d tmp %d\n", ai,tmp); if(lena - 1 < 0){ rowa[ai] = tmpc; carry = 0; } else if(tmp> 9){ while(tmp > 9){ j++; tmp = tmp - 10; } rowa[ai] = tmp; carry = j; j = 0; } else{ rowa[ai] = tmp; carry = 0; } lena--; ai--; } //if(rowa[0]==0){ // big_data_add(rowa+1,c,c,len-1+lenb-i-1-1,len-1+lenb-i-1); // printf("c[0] %d c[1] %d c[2] %d \n",c[0],c[1],c[2] ); // } // else big_data_add(rowa,c,c,len-1+lenb-i,len-1+lenb-i); } int m = len-1+lenb-i; printf("The result is : \n"); i = 0; while(c[i]==0&&i<lenr) i++; for(;i<m;i++){ printf("%d",c[i]); } printf("\n"); } // //void big_data_div(int a[],int b[],int c[],int lena,int lenb){ // //} void big_data_div(int a[],int b[],int lena,int lenb){ int i, j, k, temp, len; for(i=lena-1,j=0;i>=0;i--) x[j++]=a[i]; for(i=lenb-1,k=0;i>=0;i--) y[k++]=b[i]; if(lena<lenb) { printf("The quotient is ：0\n"); printf("The remainder is ："); for(i=0;i<lena;i++) { if(a[i]) break; } for(i = 0;i<lena;i++) printf("%d",a[i]); printf("\n"); } else { len=lena-lenb; for(i=lena-1;i>=0;i--) { if(i>=len) y[i]=y[i-len]; else y[i]=0; } lenb=lena; digit=lena; for(j=0;j<=l