BFS + 路径记录:
/* *problem ID: HDU 1026 * Author ID: fuqiang11 * TIME: 2013-07-17 * Algorithm: BFS * Status: (Accept) */ #include <iostream> #include <cstdio> #include <queue> using namespace std; #define INF 0x3f3f3f3f #define maxn 103 char map[maxn][maxn]; int N,M; int value[maxn][maxn]; //记录步数 struct point { int x; int y; }st,ed,a,pre[maxn][maxn]; //pre 记录前一个点 int xx[] = {1,-1,0,0}; int yy[] = {0,0,1,-1}; void bfs(int x,int y) { memset(value,0x3f,sizeof(value)); value[0][0] = 0; queue <point> q; st.x = x; st.y = y; q.push(st); while(!q.empty()) { a = q.front(); q.pop(); for(int i = 0; i < 4; i++) { ed.x = a.x + xx[i]; ed.y = a.y + yy[i]; if(ed.x<0||ed.x>N-1||ed.y<0||ed.y>M-1||map[ed.x][ed.y]=='X') continue; if(map[ed.x][ed.y]=='.') { if(value[a.x][a.y] + 1 < value[ed.x][ed.y]) { value[ed.x][ed.y] = value[a.x][a.y] + 1; pre[ed.x][ed.y].x = a.x; pre[ed.x][ed.y].y = a.y; q.push(ed); } } else { if(value[a.x][a.y] + map[ed.x][ed.y] - '0' + 1 < value[ed.x][ed.y]) { value[ed.x][ed.y] = value[a.x][a.y] + map[ed.x][ed.y] - '0' + 1; pre[ed.x][ed.y].x = a.x; pre[ed.x][ed.y].y = a.y; q.push(ed); } } } } } void prin_pre(int i, int j) //输出路径 { if(pre[i][j].x == -1) return ; prin_pre(pre[i][j].x, pre[i][j].y); if(map[i][j]=='.') printf("%ds:(%d,%d)->(%d,%d)\n",value[i][j],pre[i][j].x,pre[i][j].y,i,j); else { int num = map[i][j]-'0'; int t = value[i][j] - num; printf("%ds:(%d,%d)->(%d,%d)\n",t++,pre[i][j].x,pre[i][j].y,i,j); for(int k = 1; k <= num; k++) { printf("%ds:FIGHT AT (%d,%d)\n",t++,i,j); } } } int main() { while(scanf("%d%d",&N,&M)!=EOF) { getchar(); for(int i = 0; i < N; i++) gets(map[i]); pre[0][0].x = pre[0][0].y = -1; bfs(0,0); if(value[N-1][M-1]!=INF) { printf("It takes %d seconds to reach the target position, let me show you the way.\n",value[N-1][M-1]); prin_pre(N-1,M-1); } else { printf("God please help our poor hero.\n"); } puts("FINISH"); } }
DFS超时(明显的,N、M <= 100,我居然还这样做的!)
如果N.M较小的话,还是能承受的,比如10、20、30
超时的代码先挂这吧,以示警醒;
/* *problem ID: HDU 1026 * Author ID: fuqiang11 * TIME: 2013-07-16 * Algorithm: DFS * Status: (RunTimeError) */ #include <iostream> #include <cstdio> #include <cstring> #include <string> #define INF 0x3f3f3f3f using namespace std; #define maxn 103 char map[maxn][maxn]; int v[maxn][maxn]; struct Point { int x; int y; }pre[maxn][maxn]; int N,M; int xplus[] = {1,-1,0,0}; int yplus[] = {0,0,1,-1}; void dfs(int x,int y) { if(x==N-1 && y==M-1) return ; int xx,yy; for(int i = 0; i < 4; i++) { xx = x + xplus[i]; yy = y + yplus[i]; if(xx<0 || xx>N-1 || yy<0 || yy>M-1) continue; if(map[xx][yy]=='.') { if(v[x][y] + 1 < v[xx][yy]) { v[xx][yy] = v[x][y] + 1; pre[xx][yy].x = x; pre[xx][yy].y = y; dfs(xx,yy); } } if(map[xx][yy]>='1' && map[xx][yy]<='9') { if(v[x][y] + 1 + map[xx][yy] - '0' < v[xx][yy]) { v[xx][yy] = v[x][y] + 1 + map[xx][yy] - '0'; pre[xx][yy].x = x; pre[xx][yy].y = y; dfs(xx,yy); } } } } void prin_pre(int i, int j) //输出路径 { if(pre[i][j].x == -1) return ; prin_pre(pre[i][j].x, pre[i][j].y); if(map[i][j]=='.') printf("%ds:(%d,%d)->(%d,%d)\n",v[i][j],pre[i][j].x,pre[i][j].y,i,j); else { int num = map[i][j]-'0'; int t = v[i][j] - num; printf("%ds:(%d,%d)->(%d,%d)\n",t++,pre[i][j].x,pre[i][j].y,i,j); for(int k = 1; k <= num; k++) { printf("%ds:FIGHT AT (%d,%d)\n",t++,i,j); } } } int main() { while(scanf("%d%d",&N,&M)!=EOF) { cin.get(); for(int i = 0; i < N; i++) gets(map[i]); memset(v,0x3f,sizeof(v)); v[0][0] = 0; pre[0][0].x = pre[0][0].y = -1; dfs(0,0); if(v[N-1][M-1] != INF) { printf("It takes %d seconds to reach the target position, let me show you the way.\n",v[N-1][M-1]); prin_pre(N-1,M-1); } else { printf("God please help our poor hero.\n"); } puts("FINISH"); } }