高精度（大整数减法）

#include <iostream>#include <cstring>using namespace std;#define M 250inta[M];intb[M];chara1[M];charb1[M];inti,la,lb;voidinit();booljudge();voidoutput();voidoutputn();int main(){init(); int n,k;cin>>n;for(k=0;k<n;k++){cin>>a1>>b1;la=strlen(a1);lb=strlen(b1);for(i=0; i<la; i++)a[i] = a1[la-i-1]-'0';for(i=0; i<lb; i++)b[i] = b1[lb-i-1]-'0';if(judge()){for(i=0;i<la;i++){if(a[i] < b[i]){a[i+1]--;a[i]+=10;}a[i] = a[i] - b[i];}output();}else{for(i=0;i<lb;i++){if(b[i] < a[i]){b[i+1]--;b[i]+=10;}b[i] = b[i] - a[i];}outputn();}init();}return 0;}void init(){memset(a1,NULL,sizeof(a1));memset(b1,NULL,sizeof(b1));memset(a,0,sizeof(a));memset(b,0,sizeof(b));i = la = lb = 0;}bool judge(){if(la>lb){return 1;}else if(la<lb){return 0;}else {for (i=0;i<la;i++){if(a[i] > b[i]){return 1;}else if (a[i] < b[i]){return 0;}}if(i == la){return 1;}}}void output(){while(!a[la-1]){la--;if(!la){printf("0"); break;}}for(i=la-1; i>=0; i--)printf("%d",a[i]);printf("/n");}void outputn(){while(!b[lb-1]){lb--;if(!lb) {printf("0");break;}}printf("-");for(i=lb-1;i>=0;i--)printf("%d",b[i]);printf("/n");}