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I don't know why my code got WA,can anyone kindly point out what is wrong here?[/b][/b]

[cpp]
#include <iostream.h>
#include <string>
#include <math.h>

int main() {
string s1,s2;
int i,j1,j2,sign,result;
int c[10000],x[10000];
while(getline(cin,s1)) {
getline(cin,s2);
if(s2==""||(s1==""))
break;
i=0;j1=0;j2=0;
for(int k=0;k<10000;k++) {
c[k]=0;
x[k]=0;
}
sign=1;
s1=s1 ...