#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = 10010;
char a[maxn],b[maxn];
int aa[maxn],bb[maxn];
int main()
{
// freopen("a.txt","r",stdin);
while(scanf("%s%s",a,b)!=EOF)
{
memset(aa,0,sizeof(aa));
memset(bb,0,sizeof(bb));
int l1=strlen(a),l2=strlen(b),i;
int flag1=0,flag2=0;
if(a[0]=='0'&&b[0]=='0') printf("0\n"); //特殊考虑a和b都为0的情况
else
{
if(a[0]=='-')
{
flag1=1; //判断 a是否是负数 是的话置标记
for(i=0;i<l1-1;i++) //然后 a[0]是负号可以不用处理
{
aa[i]=a[l1-i-1]-'0';
}
}
else //否则 直接转换就好
{
for(i=0;i<l1;i++)
{
aa[i]=a[l1-i-1]-'0';
}
}
if(b[0]=='-') //同理判断 b
{
flag2=1;
for(i=0;i<l2-1;i++)
{
bb[i]=b[l2-i-1]-'0';
}
}
else
{
for(i=0;i<l2;i++)
{
bb[i]=b[l2-i-1]-'0';
}
}
int s=0,ans=0; //分四种情况 分别对a，b进行处理
if(!flag1&&!flag2) //a,b都为正数
{
l1=max(l1,l2);
for(i=0;i<l1;i++)
{
bb[i]+=aa[i];
if(bb[i]>=10) { bb[i]-=10; bb[i+1]++; }
}
while(!bb[l1]) l1--;
for(;l1>=0;l1--) printf("%d",bb[l1]);
printf("\n");
}
else if(!flag1&&flag2) //a为正数，b为负数
{ //判断a，b的绝对值谁大谁小
if(l1+1>l2) ans=1; //先判断长度
else if(l1+1==l2) //长度相等，判断每一位的大小
{
for(i=l1-1;i>=0;i--)
{
if(aa[i]>bb[i]) { ans=1;break;} //当前位大于 则a>b
else if(aa[i]<bb[i]) break; //否则小于
}
}
if(ans) //a的绝对值大于b 例如332 -3 或者 332 -331
{
for(i=0;i<l1;i++) //只要循环到l1-1即可
{
aa[i]-=bb[i];
if(aa[i]<0)
{
aa[i]+=10;
aa[i+1]--;
}
}
while(!aa[l1]) l1--;
for(;l1>=0;l1--) printf("%d",aa[l1]);
printf("\n");
}
else //a的绝对值小于b
{
for(i=0;i<l2-1;i++) //循环到 l2-2 ，因为b是负数
{
bb[i]-=aa[i];
if(bb[i]<0)
{
bb[i]+=10;
bb[i+1]--;
}
}
while(!bb[l2]) l2--; //如果此时 bb变成0，比如 333 -333的情况
if(l2<0) printf("0\n"); //输出0
else
{
printf("-"); //输出负号
for(;l2>=0;l2--) printf("%d",bb[l2]);
printf("\n");
}
}
}
else if(flag1&&!flag2) //和上面同理
{
if(l2+1>l1) ans=1;
else if(l2+1==l1)
{
for(i=l2-1;i>=0;i--)
{
if(bb[i]>aa[i]) { ans=1;break;}
else if(bb[i]<aa[i])break;
}
}
if(ans)
{
for(i=0;i<l2;i++)
{
bb[i]-=aa[i];
if(bb[i]<0)
{
bb[i]+=10;
bb[i+1]--;
}
}
while(!bb[l2]) l2--;
for(;l2>=0;l2--) printf("%d",bb[l2]);
printf("\n");
}
else
{
for(i=0;i<l1-1;i++)
{
aa[i]-=bb[i];
if(aa[i]<0)
{
aa[i]+=10;
aa[i+1]--;
}
}
while(!aa[l1]) l1--;
if(l1<0) printf("0\n");
else
{
printf("-");
for(;l1>=0;l1--) printf("%d",aa[l1]);
printf("\n");
}
}
}
else if(flag1&&flag2) //同为负数
{
printf("-");
l1=max(l1,l2);
for(i=0;i<l1-1;i++)
{
bb[i]+=aa[i];
s=bb[i]/10;
bb[i]%=10;
bb[i+1]+=s;
}
while(!bb[l1]) l1--;
for(;l1>=0;l1--) printf("%d",bb[l1]);
printf("\n");
}
}
}
return 0;
}
---------------------------------------------------------------------------------------------------------------------
#include <stdio.h>
#include <string.h>
#define _MAX 10005
int product[_MAX] = {0};
char numOne[_MAX] = {0}, numTwo[_MAX] = {0};
char numOneUp[_MAX] = {0}, numTwoUp[_MAX] = {0}; //倒序存储位置
int absMax = 1;
//递归进位函数
void Carrying(int tag, int i, int *p)
{
p[i] += tag;
if (p[i] > 9)
{
tag = 1;
p[i] -= 10;
Carrying(tag, i + 1, p); //写成Carrying(tag, i, j+1, p);也成立，为了让i+j递增而已
}
return ;
}
//递归退位函数
void Abdicate(int tag, int i, int *p)
{
p[i] += tag;
if (p[i] < 0)
{
tag = -1;
p[i] += 10;
Abdicate(tag, i + 1, p);
}
return ;
}
//判断大小
void size(int numOneLen, int numTwoLen)
{
int i, j;
if (numOneLen < numTwoLen)
{
absMax = 2;
for (i = 0; i < numTwoLen; i++)
{
numOneUp[i] ^= numTwoUp[i];
numTwoUp[i] ^= numOneUp[i];
numOneUp[i] ^= numTwoUp[i];
}
return ;
}
if (numOneLen == numTwoLen)
{
for (i = numOneLen - 1; i >= 0; i--)
{
if (numOneUp[i] < numTwoUp[i])
{
absMax = 2;
for (j = 0; j < numTwoLen; j++)
{
numOneUp[j] ^= numTwoUp[j];
numTwoUp[j] ^= numOneUp[j];
numOneUp[j] ^= numTwoUp[j];
}
return ;
}
else if (numOneUp[i] > numTwoUp[i])
{
return ;
}
}
}
return ;
}
//加减处理
void addOrSub(int numOneLen, int numTwoLen, int flag) //flag加法为1减法为0
{
int i, key = 0, tag, numLenMax, numLenMin;
numOneLen = numOneLen - 1;
numTwoLen = numTwoLen - 1;
//数据逆序
for (i = numOneLen; i > 0; i--)
{
numOneUp[key++] = numOne[i];
}
if (numOne[0] != '-')
{
numOneUp[key] = numOne[0];
numOneLen++;
}
key = 0;
for (i = numTwoLen; i > 0; i--)
{
numTwoUp[key++] = numTwo[i];
}
if (numTwo[0] != '-')
{
numTwoUp[key] = numTwo[0];
numTwoLen++;
}
numLenMax = numOneLen > numTwoLen ? numOneLen : numTwoLen;
numLenMin = numOneLen < numTwoLen ? numOneLen : numTwoLen;
//逐位相加
if (flag)
{
size(numOneLen, numTwoLen);
for (i = 0; i < numLenMax; i++)
{
product[i] = (int)numOneUp[i] - 48;
}
for (i = 0; i < numLenMin; i++)
{
tag = (int)numTwoUp[i]-48;
Carrying(tag, i, product); //递归
}
}
//逐位相减
else
{
size(numOneLen, numTwoLen);
for (i = 0; i < numLenMax; i++)
{
product[i] = (int)numOneUp[i] - 48;
}
for (i = 0; i < numLenMin; i++)
{
tag = -((int)numTwoUp[i]-48);
Abdicate(tag, i, product); //递归
}
}
}
//输出结果
void print()
{
int i, j;
//倒序输出结果
for (i = _MAX - 1; i > 0; i--)
{
if (product[i] != 0)
{
break; //查找到第一个不等于0的跳出
}
}
for (j = i; j >= 0; j--)
{
printf("%d",product[j]);
}
printf("\n");
}
int main(int argc, const char * argv[])
{
int numOneLen, numTwoLen;
scanf("%s %s",numOne,numTwo); //存数据
numOneLen=(int)strlen(numOne);
numTwoLen=(int)strlen(numTwo);
if (numOne[0] == '-' && numTwo[0] == '-')
{
addOrSub(numOneLen, numTwoLen, 1);
printf("-");
print();
}
else if (numOne[0] == '-' || numTwo[0] == '-')
{
addOrSub(numOneLen, numTwoLen, 0);
if ((numOne[0] == '-' && absMax == 1) || (numTwo[0] == '-' && absMax == 2))
{
printf("-");
}
print();
}
else
{
addOrSub(numOneLen, numTwoLen, 1);
print();
}
return 0;
}