1.Ignatius can only move in four directions(up, down, left, right), one step per second. A step is defined as follow: if current position is (x,y), after a step, Ignatius can only stand on (x-1,y), (x+1,y), (x,y-1) or (x,y+1).
2.The array is marked with some characters and numbers. We define them like this:
. : The place where Ignatius can walk on.
X : The place is a trap, Ignatius should not walk on it.
n : Here is a monster with n HP(1<=n<=9), if Ignatius walk on it, it takes him n seconds to kill the monster.
Your task is to give out the path which costs minimum seconds for Ignatius to reach target position. You may assume that the start position and the target position will never be a trap, and there will never be a monster at the start position.
#include<stdio.h> #include<queue> #include<stack> #include<iostream> using namespace std; typedef struct N { int i,j,time; char c; int fron,nam; friend bool operator<(N n1,N n2) { return n2.time<n1.time; } }node; node map[105][105]; stack<node> S; int dir[4][2]={{1,0},{-1,0},{0,1},{0,-1}},h,w,maxT,flog; void InStack(node Map) { node q=Map; while(q.fron!=-1) { S.push(q); q=map[q.fron/w][q.fron%w]; } S.push(q); //printf("%d\n",p); } void BFS(void) { priority_queue<node> Q; node q,p; int e,x,y,k,i; map[0][0].c='X'; map[0][0].fron=-1; q.i=0;q.j=0;q.time=0; Q.push(q); while(!Q.empty()) { q=Q.top(); Q.pop(); k=0; for(e=0;e<4;e++) { y=q.i+dir[e][0]; x=q.j+dir[e][1]; if(y>=0&&y<h&&x>=0&&x<w&&map[y][x].c!='X') { map[y][x].fron=map[q.i][q.j].nam; if(map[y][x].c=='.') map[y][x].time=q.time+1; else map[y][x].time=q.time+map[y][x].c-'0'+1; map[y][x].c='X'; p.i=y; p.j=x;p.time=map[y][x].time; if(p.i==h-1&&p.j==w-1) { maxT=map[h-1][w-1].time; InStack(map[h-1][w-1]); flog=1; //printf("%d\n",maxT); return ; } Q.push(p); } } } } int main() { int i,j,t; node q,p; while(scanf("%d%d",&h,&w)>0) { t=0; for(i=0;i<h;i++) { getchar(); for(j=0;j<w;j++) { scanf("%c",&map[i][j].c); map[i][j].i=i; map[i][j].j=j; map[i][j].nam=t++; } } if(map[h-1][w-1].c=='X') { printf("God please help our poor hero.\n"); printf("FINISH\n"); continue ; } flog=0; BFS(); if(!flog) printf("God please help our poor hero.\n"); else { p=S.top(); S.pop();//printf("%d\n",map[1][4].time); printf("It takes %d seconds to reach the target position, let me show you the way.\n",maxT); for(i=1;i<=maxT;i++) { if(p.time<i) { q=S.top(); S.pop(); } if(p.time<i) printf("%ds:(%d,%d)->(%d,%d)\n",i,p.i,p.j,q.i,q.j); else printf("%ds:FIGHT AT (%d,%d)\n",i,p.i,p.j); p=q; } } printf("FINISH\n"); } }