errors made,
boundary conditions, <= vs < ,
decreasing vs increasing , ++, –,
‘0’/’1’ vs 0/1
prototype of sum, return the starting position of c-style string containing the sum, just like sprintf return number of characters successfully read.
p1=sum(p1,p2);
and
p=sprintf(p,"%09d",x);
have some similarities.
#include <cstdio>
#include <cstring>
char* sum(char *to, char *from) {
static const int charzero='0',oublecharzero='0'+'0';
int sz1=strlen(to), sz2=strlen(from), nszmax,nszmin, i,j, tmp,carry;
if(sz1>=sz2) { nszmax=-sz2, nszmin=-sz1; }
else { nszmax=-sz1, nszmin=-sz2; }
to+=sz1, from+=sz2;
for(carry=0,i=-1;i>=nszmax;--i) {
tmp=carry+to[i]+from[i]-doublecharzero;
to[i]=charzero+tmp%10; carry=tmp/10;
}
if(sz2>sz1) {
for(j=i;j>=nszmin;--j) to[j]=from[j];
sz1=sz2;
}
if(carry) {
for(j=i;j>=nszmin && to[j]=='9';--j) to[j]='0';
if(j<nszmin) { to[j]='1'; ++sz1; }
else { ++to[j]; }
}
return to-sz1;
}
int main() {
//freopen("input.txt","r",stdin);
const int MAXSIZE=101;
int ncase,i,j;
char buf1[MAXSIZE+2]={0}, buf2[MAXSIZE+2]={0}, *p1,*p2;
scanf("%d",&ncase);
for(i=1;i<=ncase;++i) {
p1=buf1+MAXSIZE, p2=buf2; p1[0]='0', p1[1]=0;
while(scanf("%100s",p2)==1 && strcmp(p2,"0")!=0) {
p1=sum(p1,p2);
}
puts(p1); if(i!=ncase) putchar('
');
}
return 0;
}
版权声明:本文为博主原创文章,未经博主允许不得转载。// p.s. If in any way improment can be achieved, better performance or whatever, it will be well-appreciated to let me know, thanks in advance.