Problem ONEZERO from SPOJ

ONEZERO.cpp

@@ -0,0 +1,56 @@
+// Problem : ONEZERO from SPOJ
+
+#include <bits/stdc++.h>
+using namespace std;
+#define ll long long
+
+int par[25001];
+char dig[25001];
+
+void solve(){
+	int n,i,v1,v2,end,cur;
+	string res = "";
+	cin>>n;
+	for(i=0;i<=n;i++)par[i] = -1,dig[i] =  '0';
+	par[1] = 1;
+
+	queue<int> q;
+	q.push(1);
+
+	while(!q.empty()){
+		cur = q.front();
+		q.pop();
+
+		v1 = (cur*10)%n;
+		v2 = (v1+1)%n;
+
+		if(par[v1] == -1){
+			par[v1] = cur;
+			dig[v1] = '0';
+			q.push(v1);
+		}
+
+		if(par[v2] == -1){
+			par[v2] = cur;
+			dig[v2] = '1';
+			q.push(v2);
+		}
+	}
+
+	end = 0;
+	while(par[end]!=end){
+		res+=dig[end];
+		end = par[end];
+	}
+	res+='1';
+	reverse(res.begin(),res.end());
+	cout<<res<<"\n";
+	return ;
+}
+
+int main(){
+	int t;
+	cin>>t;
+	while(t--)solve();
+	return 0;
+}