A + B Problem II（1002）

hdu1002

题意：大数相加

 

#include<bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <string>
#include <stdio.h>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <string.h>
#include <vector>
typedef long long ll ;
#define int ll
#define mod 1000000007
#define gcd __gcd
#define rep(i , j , n) for(int i = j ; i <= n ; i++)
#define red(i , n , j)  for(int i = n ; i >= j ; i--)
#define ME(x , y) memset(x , y , sizeof(x))
//ll lcm(ll a , ll b){return a*b/gcd(a,b);}
ll quickpow(ll a , ll b){ll ans=1;while(b){if(b&1)ans=ans*a%mod;b>>=1,a=a*a%mod;}return ans;}
//int euler1(int x){int ans=x;for(int i=2;i*i<=x;i++)if(x%i==0){ans-=ans/i;while(x%i==0)x/=i;}if(x>1)ans-=ans/x;return ans;}
//const int N = 1e7+9; int vis[n],prime[n],phi[N];int euler2(int n){ME(vis,true);int len=1;rep(i,2,n){if(vis[i]){prime[len++]=i,phi[i]=i-1;}for(int j=1;j<len&&prime[j]*i<=n;j++){vis[i*prime[j]]=0;if(i%prime[j]==0){phi[i*prime[j]]=phi[i]*prime[j];break;}else{phi[i*prime[j]]=phi[i]*phi[prime[j]];}}}return len}
#define SC scanf
#define INF  0x3f3f3f3f
#define PI acos(-1)
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define all(v) v.begin(),v.end()
#define size(v) (int)(v.size())
#define lson l,mid,root<<1
#define rson mid+1,r,root<<1|1
using namespace std;
const int N = 1e6+7;
const int maxn = 5e2+9;
int cnt ;
string plu(string a , string b){//大数加最优版本
    int i , j ; if(size(a) < size(b)) swap(a , b);//a长度更长
    for(i = size(a)-1 , j = size(b)-1 ; i >= 0 ; i-- , j--){//不逆置，直接从后双指针模拟
        a[i] = a[i] + (j >=0 ? b[j] - '0' : 0) ;
        if(a[i]-'0' >= 10){
            a[i] = a[i] - 10 ;
            if(i) a[i-1]++;
            else a = '1' + a ;//答案只可能比a长度长1且为1.
        }
    }
    return a;
}
void solve(){
    if(cnt) cout << endl;
    string a , b ;
    cin >> a >> b;
    cout << "Case " << ++cnt << ":" << endl;
    cout << a << " + " << b << " = " << plu(a , b) << endl;
}

signed main()
{
    //ios_base::sync_with_stdio(false);
    //cin.tie(NULL);cout.tie(NULL);
    int _ ;cin>>_;while(_--)
        solve();
}