A. 直接从状态(0,0)bfs, 这样一定是最小的
#include <iostream> #include <sstream> #include <algorithm> #include <cstdio> #include <math.h> #include <set> #include <map> #include <queue> #include <string> #include <string.h> #include <bitset> #define REP(i,a,n) for(int i=a;i<=n;++i) #define PER(i,a,n) for(int i=n;i>=a;--i) #define hr putchar(10) #define pb push_back #define lc (o<<1) #define rc (lc|1) #define mid ((l+r)>>1) #define ls lc,l,mid #define rs rc,mid+1,r #define x first #define y second #define io std::ios::sync_with_stdio(false) #define endl '\n' #define DB(a) ({REP(__i,1,n) cout<<a[__i]<<' ';hr;}) using namespace std; typedef long long ll; typedef pair<int,int> pii; const int P = 1e9+7, INF = 0x3f3f3f3f; ll gcd(ll a,ll b) {return b?gcd(b,a%b):a;} ll qpow(ll a,ll n) {ll r=1%P;for (a%=P;n;a=a*a%P,n>>=1)if(n&1)r=r*a%P;return r;} ll inv(ll x){return x<=1?1:inv(P%x)*(P-P/x)%P;} inline int rd() {int x=0;char p=getchar();while(p<'0'||p>'9')p=getchar();while(p>='0'&&p<='9')x=x*10+p-'0',p=getchar();return x;} //head #ifdef ONLINE_JUDGE const int N = 1e6+10; #else const int N = 111; #endif int d, s; int vis[530][5030]; pii pre[530][5030]; void bfs() { queue<pii> q; q.push(pii(0,0)); vis[0][0] = 1; while (q.size()) { int x=q.front().x,y=q.front().y; q.pop(); REP(i,0,9) if (y+i<=s) { int xx=(x*10+i)%d,yy=y+i; if (!vis[xx][yy]) { vis[xx][yy] = 1; pre[xx][yy]=pii(x,y); q.push(pii(xx,yy)); } } } } void dfs2(int x, int y) { if (x||y) { dfs2(pre[x][y].x,pre[x][y].y); printf("%d",y-pre[x][y].y); } } int main() { scanf("%d%d", &d, &s); bfs(); if (!vis[0][s]) return puts("-1"),0; dfs2(0,s),hr; }