[BFS] 机器人搬重物 洛谷
本文章仅纪念自己 把200多行代码压到80多行
https://www.luogu.org/problemnew/show/P1126
vj上也有 csu1975 说真的 直接输出12 在csu上就过了 洛谷数据多点
23333 太可怕了 一年后看到给改了改
改版后
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 50+5;
const int cx[]= {0,0,1,-1};
const int cy[]= {1,-1,0,0};
const int xx[]= {-1,0,-1,0};
const int yy[]= {-1,-1,0,0};
const int walkx[]= {1,0,-1,0};
const int walky[]= {0,-1,0,1};
const char tof[]="SWNE";
int n,m,x,pos,sx,sy,ex,ey,flag;
int mp[maxn][maxn];
bool vis[maxn][maxn][26];
bool check(int x,int y,char s) {
if(x==1||y==1) return 1;
if(x<1||y<1||x>n||y>m) return 1;
if(vis[x][y][s-'A']) return 1;
for(int i=0; i<4; i++)
if(mp[x+xx[i]][y+yy[i]]==1) return 1;
return 0;
}
int repos(char s) {
for(int i=0; i<4; i++) if(tof[i]==s) return i;
}
struct node {
int sp;
char ms;
int x,y;
} st,tp,tmp;
void bfs() {
queue<node> que;
que.push(st);
vis[st.x][st.y][st.ms-'A']=1;
while(!que.empty()) {
tmp=que.front();
que.pop();
if(tmp.x==ex&&tmp.y==ey) {
printf("%d\n",tmp.sp);
return ;
}
for(int i=0; i<4; i++) {
pos=repos(tmp.ms);
tp.ms=tmp.ms;
if(i==0) {
tp.ms=tof[(pos+1)%4];
if(!check(tmp.x,tmp.y,tp.ms)) {
vis[tmp.x][tmp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tmp.x,tmp.y});
}
tp.ms=tof[(pos+3)%4];
if(!check(tmp.x,tmp.y,tp.ms)) {
vis[tmp.x][tmp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tmp.x,tmp.y});
}
} else {
tp.x=tmp.x+walkx[pos]*(4-i);
tp.y=tmp.y+walky[pos]*(4-i);
flag=1;
for(int j=3-i; j>=0; j--)
if(check(tp.x+(-1)*j*walkx[pos],tp.y+(-1)*j*walky[pos],tp.ms)) flag=0;
if(flag) vis[tp.x][tp.y][tp.ms-'A']=1,que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
}
}
printf("-1\n");
return ;
}
int main() {
scanf("%d %d",&n,&m);
for(int i=1; i<=n; i++) for(int j=1; j<=m; j++)
scanf("%d",&mp[i][j]);
scanf("%d %d %d %d %c",&sx,&sy,&ex,&ey,&st.ms);
st=node {0,st.ms,sx+1,sy+1};
ex++,ey++,n++,m++;
bfs();
return 0;
}
改版前
#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <list>
using namespace std;
typedef long long ll;
const int maxn = 50+5;
const int cx[]= {0,0,1,-1};
const int cy[]= {1,-1,0,0};
const int xx[]={-1,0,-1,0};
const int yy[]={-1,-1,0,0};
int n,m,x;
int mp[maxn][maxn];
bool vis[maxn][maxn][26];
int sx,sy,ex,ey;
bool check(int x,int y,char s) {
if(x==1||y==1) return 1;
if(x<1||y<1||x>n||y>m) return 1;
if(vis[x][y][s-'A']) return 1;
for(int i=0; i<4; i++) {
if(mp[x+xx[i]][y+yy[i]]==-1) return 1;
}
return 0;
}
struct node {
int sp;
char ms;
int x,y;
} st,tp,tmp;
void bfs() {
queue<node> que;
que.push(st);
vis[st.x][st.y][st.ms-'A']=1;
while(!que.empty()) {
tmp=que.front();
que.pop();
// cout<<tmp.x<<" "<<tmp.y<<" "<<tmp.ms<<" "<<tmp.sp<<endl;
if(tmp.x==ex&&tmp.y==ey) {
printf("%d\n",tmp.sp);
return ;
}
int nx,ny;
for(int i=0; i<5; i++) {
if(i==0) {
if(tmp.ms=='S') tp.ms='W';
if(tmp.ms=='W') tp.ms='N';
if(tmp.ms=='N') tp.ms='E';
if(tmp.ms=='E') tp.ms='S';
if(check(tmp.x,tmp.y,tp.ms)) continue;
vis[tmp.x][tmp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tmp.x,tmp.y});
}
if(i==1) {
if(tmp.ms=='S') tp.ms='E';
if(tmp.ms=='W') tp.ms='S';
if(tmp.ms=='N') tp.ms='W';
if(tmp.ms=='E') tp.ms='N';
if(check(tmp.x,tmp.y,tp.ms)) continue;
vis[tmp.x][tmp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tmp.x,tmp.y});
}
if(i==4) {
if(tmp.ms=='N') {
tp.ms=tmp.ms;
tp.y=tmp.y;
tp.x=tmp.x-1;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='S') {
tp.ms=tmp.ms;
tp.y=tmp.y;
tp.x=tmp.x+1;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='W') {
tp.ms=tmp.ms;
tp.y=tmp.y-1;
tp.x=tmp.x;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='E') {
tp.ms=tmp.ms;
tp.y=tmp.y+1;
tp.x=tmp.x;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
}
if(i==3) {
if(tmp.ms=='N') {
tp.ms=tmp.ms;
tp.y=tmp.y;
tp.x=tmp.x-2;
if(check(tp.x+1,tp.y,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='S') {
tp.ms=tmp.ms;
tp.y=tmp.y;
tp.x=tmp.x+2;
if(check(tp.x-1,tp.y,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='W') {
tp.ms=tmp.ms;
tp.y=tmp.y-2;
tp.x=tmp.x;
if(check(tp.x,tp.y+1,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='E') {
tp.ms=tmp.ms;
tp.y=tmp.y+2;
tp.x=tmp.x;
if(check(tp.x,tp.y-1,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
}
if(i==2) {
if(tmp.ms=='N') {
tp.ms=tmp.ms;
tp.y=tmp.y;
tp.x=tmp.x-3;
if(check(tp.x+2,tp.y,tp.ms)) continue;
if(check(tp.x+1,tp.y,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='S') {
tp.ms=tmp.ms;
tp.y=tmp.y;
tp.x=tmp.x+3;
if(check(tp.x-2,tp.y,tp.ms)) continue;
if(check(tp.x-1,tp.y,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='W') {
tp.ms=tmp.ms;
tp.y=tmp.y-3;
tp.x=tmp.x;
if(check(tp.x,tp.y+2,tp.ms)) continue;
if(check(tp.x,tp.y+1,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
if(tmp.ms=='E') {
tp.ms=tmp.ms;
tp.y=tmp.y+3;
tp.x=tmp.x;
if(check(tp.x,tp.y-2,tp.ms)) continue;
if(check(tp.x,tp.y-1,tp.ms)) continue;
if(check(tp.x,tp.y,tp.ms)) continue;
vis[tp.x][tp.y][tp.ms-'A']=1;
que.push(node {tmp.sp+1,tp.ms,tp.x,tp.y});
}
}
}
}
printf("-1\n");
return ;
}
int main() {
scanf("%d %d",&n,&m);
memset(mp,-1,sizeof(mp));
for(int i=1; i<=n; i++) {
for(int j=1; j<=m; j++) {
scanf("%d",&x);
if(x==1) continue;
else mp[i][j]=x;
}
}
n++,m++;
scanf("%d %d %d %d %c",&sx,&sy,&ex,&ey,&st.ms);
st=node{0,st.ms,sx+1,sy+1};
ex++,ey++;
bfs();
return 0;
}
（真心发问）