【HDOJ】1104 Remainder

bfs.

 #include <cstdio>
 #include <cstring>
 #include <cstdlib>
 #include <queue>
 #include <iostream>
 #include <string>
 using namespace std;

 #define MAXN 1005

 char ops[] = "+-*%";
 bool visit[MAXN];
 int n, m, k;
 string op;

 typedef struct node_t {
     int s, n;
     string op;
     node_t (int ss, int nn, string opp) {
         s = ss;
         n = nn;
         op = opp;
     }
 } node_t;

 int bfs() {
     queue<node_t> Q;
     int ns[], tmp;
     int nn = ((n+)%k+k)%k;
     int mk = m*k;

     Q.push(node_t(, n, ""));
     memset(visit, false, sizeof(visit));
     visit[(n%k+k)%k] = true;

     while(!Q.empty()) {
         node_t nd = Q.front();
         Q.pop();
         // +
         ns[] = (nd.n + m)%mk;
         // -
         ns[] = (nd.n - m)%mk;
         // *
         ns[] = (nd.n * m)%mk;
         // %
         ns[] = (nd.n % m+m)%m%mk;
         for (int i=; i<; ++i) {
             tmp = (ns[i]%k+k)%k;
             if (tmp == nn) {
                 op = nd.op + ops[i];
                 return nd.s+;
             }
             if (!visit[tmp]) {
                 visit[tmp] = true;
                 Q.push(node_t(nd.s+, ns[i], nd.op+ops[i]));
             }
         }
     }

     return ;
 }

 int main() {
     int ans;

 #ifndef ONLINE_JUDGE
     freopen("data.in", "r", stdin);
 #endif

     while (scanf("%d%d%d", &n, &k, &m)!=EOF && (n||m||k)) {
         ans =  bfs();
         printf("%d\n", ans);
         if (ans)
             cout <<op<<endl;
     }

     return ;
 }