[高精度乘法]BZOJ 1754 [Usaco2005 qua]Bull Math

Posted 2020-10-09

模板题目，练练手~

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
using namespace std;

int s1[2333];
int s2[2333];
int Out[2333];
string one,two;

void Debug(){
    for(int i=0;i<one.length();i++){
        printf("%d",s1[i]);
    }
    printf("\n");
    for(int i=0;i<two.length();i++){
        printf("%d",s2[i]);
    }
}

int main(){
    cin>>one;
    cin>>two;
    if(one.length() < two.length() ) swap(one,two);    
    for(int i=0;i<one.length();i++){
        s1[i] = one[i] - ‘0‘;
    }
    for(int i=0;i<two.length();i++){
        s2[i] = two[i] - ‘0‘;
    }
    for(int i=two.length()-1;i>=0;i--){
        int pos = two.length() - i - 1;
        for(int j=one.length()-1;j>=0;j--,pos++){
            Out[pos]+=s2[i]*s1[j];
            Out[pos+1] += Out[pos] / 10;
            Out[pos]%=10;
        }
        /*for(int fuck = 4;fuck>=0;fuck--) printf("%d",Out[i]);
        printf("\n");*/
    }
    int i  = one.length() + two.length();
    while( Out[i]==0 ) i--;
    for(;i>=0;i--) printf("%d",Out[i]);
    return 0;
    //for(int i=one.length();)
}