C语言高精度计算

高精度乘法

#include "pch.h"
#include <iostream>
#include <stdlib.h>

int main()
{
char n1[1500], n2[1500];
int a[1500] = {'\0'};
int b[1500] = {'\0'};
int c[3000] = {0};
int m, n, i, j, o;
printf("请输入被乘数:\n");
scanf_s("%s",&n1,128);
m = strlen(n1);
printf("请输入乘数:\n");
scanf_s("%s",&n2,128);
n = strlen(n2);
if(m>n){o = m;}else{o = n;}
//将char类型的元素转换成int类型
for (i = 0, j = m - 1; i < m; i++, j--) {
a[i] = n1[j] - '0';
}
//将char类型的元素转换成int类型
for (i = 0, j = n - 1; i < n; i++, j--) {
b[i] = n2[j] - '0';
}
//用数组a的每一位跟数组b进行乘法操作
for (i = 0; i < m;i++) {
for (j = 0; j < n; j++) {
c[i + j] = c[i+j]+(a[i] * b[j]);
}
}
//处理进位
for (i = 0; i < m + n; i++) { if (c[i] >= 10) {//若该位大于10则向前进该处元素的十位数
c[i + 1] = c[i+1] + c[i] / 10;//20=>2,10=>1
c[i] = c[i] % 10;//取个位数
}
}
//由于存储c时是逆序存储,所以要再次逆序输出
for (i = o-1; i >=0;i--) {
printf("%d",c[i]);
}
printf("\n");
system("pause");
}

---

高精度加法

#include "pch.h"
#include <iostream> 
#include <stdlib.h>

int main()
{
    char n1[1500], n2[1500];
    int a[1500] = {'\0'};
    int b[1500] = {'\0'};
    int c[3000] = {0};
    int m, n, i, j,o;
    printf("请输入被加数:\n");
    scanf_s("%s",&amp;amp;n1,128);
    m = strlen(n1);
    printf("请输入加数:\n");
    scanf_s("%s",&amp;amp;n2,128);
    n = strlen(n2);
    for (i = 0, j = m - 1; i &amp;lt; m; i++, j--) {
        a[i] = n1[j]-'0' ;
    }
    for (i = 0, j = n - 1; i &amp;lt; n; i++, j--) { b[i] = n2[j]-'0' ; } if (m &amp;gt; n) { o = m; }
    else { o = n; }
    for (i = 0; i &amp;lt; o;i++) {
            c[i] = c[i]+(a[i] + b[i]);
    }
    for (i = 0; i &amp;lt; o; i++) { if (c[i] &amp;gt;= 10) {
            c[i + 1] =c[i+1]+( c[i] / 10);
            c[i] = c[i] % 10;
        }
}
    for (i = o-1; i &amp;gt;=0;i--) {
        printf("%d",c[i]);
    }
    printf("\n");
    system("pause");
}

---

高精度减法

#include "pch.h"
#include <iostream> 
#include <stdlib.h>

int main()
{
    char n1[1500], n2[1500];
    int a[1500] = { '\0' };
    int b[1500] = { '\0' };
    int c[3000] = { 0 };
    int m, n, i, j, o,flag=0;
    printf("请输入被减数:\n");
    scanf_s("%s", &amp;amp;n1, 128);
    m = strlen(n1);
    printf("请输入减数:\n");
    scanf_s("%s", &amp;amp;n2, 128);
    n = strlen(n2);
    for (i = 0, j = m - 1; i &amp;lt; m; i++, j--) {
        a[i] = n1[j] - '0';
    }
    for (i = 0, j = n - 1; i &amp;lt; n; i++, j--) { b[i] = n2[j] - '0'; } if (m &amp;gt; n) { o = m; }
    else { o = n; }
    for (i = 0; i &amp;lt; o; i++) {
        c[i] = c[i] + (a[i] - b[i]);
    }
    for (i = 0; i &amp;lt; o; i++) {
        if (c[i] &amp;lt; 0 &amp;amp;&amp;amp; flag != 1) { flag = 1; }//记录正负号
        if (c[i] &amp;lt; 0 &amp;amp;&amp;amp; a[i] == 0) { c[i + 1] = c[i + 1] - 1; c[i] = 10 - b[i]; } if (b[i] == 0 &amp;amp;&amp;amp; c[i] &amp;gt; 0) {
            c[i] = 10 - a[i];
            if (c[i + 1] &amp;gt; 0) { c[i + 1] = c[i + 1] - 1; }
            else {
                c[i + 1] = c[i + 1] + 1;
            }
        }
        if (c[i] &amp;lt; 0) { c[i] = -1 * c[i]; } } if (flag == 1) { printf("-"); } for (i = o-1; i &amp;gt;=0;i--) {
        printf("%d",c[i]);
    }
    printf("\n");
    system("pause");
}

---

高精度除低精度

#include "pch.h"
#include <iostream> 
#include <stdlib.h>

int main()
{
    char n1[1500];
    int n2;
    double a[3000] = { '\0' }, b[3000] = { 0 }, c = 0;
    int m, n, i, j, o,flag=0;
    printf("请输入被除数:\n");
    scanf_s("%s", &amp;amp;amp;n1, 128);
    m = strlen(n1);
    printf("请输入除数:\n");
    scanf_s("%d", &amp;amp;amp;n2, 128);
    if (n2 == 0) { printf("除数不可为0\n"); system("pause"); exit(0); }
    for (i = 0, j = m - 1; i &amp;amp;lt; m; i++, j--) {
        a[i] = n1[j] - '0';
    }
    for (i = 0,j=0; i &amp;amp;lt; m;i++,j++) { b[i] = b[i] + (a[i] / n2); for (o=j; o&amp;amp;gt;0; o--) {
            b[i] = b[i] * 10;
        }
    }
    for (i = 0; i&amp;amp;lt;m; i++) {
        c = c + b[i];
    }
    printf("%lf",c);
    printf("\n");
    system("pause");
}

原理:使用被除数的每一位进行除法运算,并将最终结果sum起来