HDU 1026 Ignatius and the Princess I (priority queue + print path)

Test instructions: N*m maze, from (0,0) to (n-1,m-1), Encounter monster stay monster in the box of the number of units time, to find the shortest time and print the path;

Idea: Use BFS first search the shortest road, search the shortest way must use priority queue, otherwise the result is not correct; Save the path by saving the previous step, when you reach the end, the path is queried, and the monster is in the same position;

#include <cstdio>#include<cstring>#include<queue>#include<algorithm>using namespacestd;intN,m,s1,s2,e1,e2;Charmm[505][505];intvis[505][505];intdir[4][2]={{1,0},{-1,0},{0,1},{0,-1}};structnode{intx,y,t; BOOL operator< (ConstNODE&AMP;XX)Const    {        returnT>xx.t; }};structlujin{intX1,y1,x2,y2;} record[505];node pre[505][505];intquan[505][505],route[505][505];intBFs () {priority_queue<node>Q; VIS[S1][S2]=1;    Node Cur,now;    node S; S.x=s1;s.y=s2;s.t=0;    Q.push (s);  while(!Q.empty ()) {cur=Q.top ();        Q.pop ();  for(intI=0;i<4; i++) {now.x=cur.x+dir[i][0]; Now.y=cur.y+dir[i][1]; NOW.T=cur.t+1; if(now.x<0|| now.x>=n| | now.y<0|| now.y>=m| | vis[now.x][now.y]| | mm[now.x][now.y]=='X')Continue; if(mm[now.x][now.y]>='1'&&mm[now.x][now.y]<='9') {now.t+=mm[now.x][now.y]-'0'; }             if(now.x== (n1) &&now.y== (M-1))//get to the end, rewind to find the path            {                intnum=0, TEMP1,TEMP2; E1=now.x;e2=now.y; PRE[NOW.X][NOW.Y]=cur;  while(e1!=0|| e2!=0)//or the relationship!! Not with, small bug debug for a long time ...                 {                                    if(mm[e1][e2]>='1'&&mm[e1][e2]<='9')                    {                        for(intj=0; j<mm[e1][e2]-'0'; j + +) {record[now.t-num].x1=pre[e1][e2].x; RECORD[NOW.T-num].y1=pre[e1][e2].y; RECORD[NOW.T-num].x2=E1; RECORD[NOW.T-num].y2=E2; Num++; }} record[now.t-num].x1=pre[e1][e2].x; RECORD[NOW.T-num].y1=pre[e1][e2].y; RECORD[NOW.T-num].x2=E1; RECORD[NOW.T-num].y2=E2; Temp1=pre[e1][e2].x; Temp2=pre[e1][e2].y; //printf ("(%d,%d) (%d,%d) \ n", E1,E2,TEMP1,TEMP2);E1=temp1;e2=Temp2; Num++; }                returnnow.t; } Vis[now.x][now.y]=1;            Q.push (now); PRE[NOW.X][NOW.Y]=cur;//Save the previous step        }    }    return-1;}intMain () {intI,j,k,ans;  while(SCANF ("%d%d", &n,&m)! =EOF) {memset (mm,0,sizeof(mm)); memset (Vis,0,sizeof(VIS)); Memset (Quan,0,sizeof(Quan)); memset (PRE,0,sizeof(pre)); memset (Route,0,sizeof(route)); memset (Record,0,sizeof(record));  for(i=0; i<n;i++)        {             for(j=0; j<m;j++) {scanf ("%c",&Mm[i][j]); S1=0, s2=0; }} ans=BFS (); if(ans==-1) printf ("God Poor hero.\n"); Elseprintf"It takes%d seconds to reach the target position, let me show you the way.\n", ans); if(ans!=-1)        {             for(i=1; i<=ans;i++) {printf ("%ds:", i); if(record[i-1].x2==record[i].x2&&record[i-1].y2==record[i].y2) printf ("fight at (%d,%d) \ n", Record[i].x2,record[i].y2); Elseprintf ("(%d,%d) (%d,%d) \ n", Record[i].x1,record[i].y1,record[i].x2,record[i].y2); }} printf ("finish\n"); }}

HDU 1026 Ignatius and the Princess I (priority queue + print path)