杭电hdu 1026 Ignatius and the Princess I 广度优先搜索

//深度优先搜索
#include <iostream>

using namespace std;

#define MAX 101

typedef struct _node
{
int x;
int y;
}node;

int n, m;

node road[MAX*MAX];
node roadtmp[MAX*MAX];
int k, t;

char map[MAX][MAX];

bool used[MAX][MAX];

int dir[4][2] = {-1, 0, 1, 0, 0, -1, 0, 1};

int sum, sumtmp;

void dfs(node start)
{
if(sum < sumtmp)return;
if(start.x == n-1 && start.y == m-1){
if(sum > sumtmp){
sum = sumtmp;
t = k;
for(int i = 0; i < k; i ++){
road[i].x = roadtmp[i].x;
road[i].y = roadtmp[i].y;
}
}
return;
}
for(int i = 0; i < 4; i ++){
node tmp;
tmp.x = start.x + dir[i][0];
tmp.y = start.y + dir[i][1];
if(tmp.x >= 0&&tmp.x < n&&tmp.y >= 0&&tmp.y < m){
if(!used[tmp.x][tmp.y]&&map[tmp.x][tmp.y] != '#'){
if(map[tmp.x][tmp.y] == '.'){
used[tmp.x][tmp.y] = true;
roadtmp[k].x = tmp.x;
roadtmp[k].y = tmp.y;
sumtmp += 1;
k ++;
dfs(tmp);
k --;
sumtmp -= 1;
used[tmp.x][tmp.y] = false;
}
else if(map[tmp.x][tmp.y] >= '0' && map[tmp.x][tmp.y] <= '9'){
used[tmp.x][tmp.y] = true;
roadtmp[k].x = tmp.x;
roadtmp[k].y = tmp.y;
sumtmp += 1;
sumtmp += map[tmp.x][tmp.y] - '0';
k ++;
dfs(tmp);
k --;
sumtmp -= map[tmp.x][tmp.y] - '0';
sumtmp -= 1;
used[tmp.x][tmp.y] = false;
}
}
}
}
}

int main()
{
//	freopen("input.txt", "r", stdin);
int i, j;
while(scanf("%d%d", &n, &m)!=EOF){
//		scanf("%*c");
memset(used, false, sizeof(used));
k = 0;
t = 0x7fffffff;
sum = 0x7fffffff;
sumtmp = 0;
for(i = 0; i < n; i ++){
for(j = 0; j < m; j ++){
scanf(" %c", &map[i][j]);
}
}
node st;
st.x = st.y = 0;
used[0][0] = true;
dfs(st);

if(t == 0x7fffffff)printf("God please help our poor hero.\n");
else {
printf("It takes %d seconds to reach the target position, let me show you the way.\n", sum);
int l = 1;
for(i = 0; i < t; i ++){
if(i != 0){
printf("%ds:(%d,%d)->(%d,%d)\n", l ++, road[i-1].x, road[i-1].y, road[i].x, road[i].y);
if(map[road[i].x][road[i].y] >= '0' && map[road[i].x][road[i].y] <= '9'){
int r = map[road[i].x][road[i].y]-'0';
while(r--){
printf("%ds:FIGHT AT (%d,%d)\n", l ++, road[i].x, road[i].y);
}
}
}
else{
printf("%ds:(0,0)->(%d,%d)\n", l ++, road[i].x, road[i].y);
if(map[road[i].x][road[i].y] >= '0' && map[road[i].x][road[i].y] <= '9'){
int r = map[road[i].x][road[i].y]-'0';
while(r--){
printf("%ds:FIGHT AT (%d,%d)\n", l ++, road[i].x, road[i].y);
}
}
}
}
}
printf("FINISH\n");
}
return 0;
}

//广度优先搜索
#include <iostream>

using namespace std;

#define MAX 101

#include <queue>
#include <stack>

typedef struct _node
{
int x;
int y;
int x_next;
int y_next;
int seconds;
friend bool operator<(_node a, _node b){return a.seconds > b.seconds;}
}node;

node path[MAX][MAX];

char map[MAX][MAX];

bool used[MAX][MAX];

int n, m;

priority_queue<node > q;
node end;
stack<node > S;

int dir[4][2] = {-1, 0, 1, 0, 0, -1, 0, 1};

int bfs()
{
int i;
node tmp, no_pre;
while(!q.empty()){
no_pre = q.top();
if(no_pre.x == n-1 && no_pre.y == m-1){
end.x = no_pre.x;
end.y = no_pre.y;
end.x_next = 0;
end.y_next = 0;
return no_pre.seconds;
}
q.pop();
for(i = 0; i < 4; i ++){
tmp.x = no_pre.x + dir[i][0];
tmp.y = no_pre.y + dir[i][1];
if(tmp.x >= 0 && tmp.x < n && tmp.y >= 0 && tmp.y < m &&!used[tmp.x][tmp.y] && map[tmp.x][tmp.y] != 'X'){
if(map[tmp.x][tmp.y] == '.'){
tmp.seconds = no_pre.seconds + 1;
}
else if(map[tmp.x][tmp.y] >= '0' && map[tmp.x][tmp.y] <= '9'){
tmp.seconds = no_pre.seconds + 1 + (int)(map[tmp.x][tmp.y] - '0');
}
used[tmp.x][tmp.y] = true;
q.push(tmp);
no_pre.x_next = tmp.x;
no_pre.y_next = tmp.y;
path[tmp.x][tmp.y] = no_pre;
}//if
}//for
}//while
return -1;
}

int main()
{
//	freopen("input.txt", "r", stdin);
int i, j;
while(scanf("%d%d", &n, &m)!=EOF){
for(i = 0; i < n; i ++){
for(j = 0; j < m; j ++){
scanf(" %c", &map[i][j]);
}
}
memset(used, false, sizeof(used));
while(!q.empty())q.pop();
node no_start;
no_start.x = no_start.y = no_start.seconds = 0;
used[0][0] = true;
q.push(no_start);
int flag = bfs();
if(flag == -1)printf("God please help our poor hero.\n");
else {
printf("It takes %d seconds to reach the target position, let me show you the way.\n", flag);
S.push(end);
node temp = path[end.x][end.y];
while(temp.x||temp.y){
S.push(temp);
temp = path[temp.x][temp.y];
}
S.push(temp);
int num = 1;
while(!S.empty()){
temp = S.top();
S.pop();
if(map[temp.x][temp.y] == '.' && !(temp.x_next == 0 && temp.y_next == 0)){
printf("%ds:(%d,%d)->(%d,%d)\n", num ++, temp.x, temp.y, temp.x_next, temp.y_next);
}
else if(map[temp.x][temp.y] >= '0' && map[temp.x][temp.y] <= '9'){
int t = map[temp.x][temp.y] - '0';
while(t --){
printf("%ds:FIGHT AT (%d,%d)\n", num ++, temp.x, temp.y);
}
if(!(temp.x_next == 0 && temp.y_next == 0)){
printf("%ds:(%d,%d)->(%d,%d)\n", num ++, temp.x, temp.y, temp.x_next, temp.y_next);
}
}
}
}
printf("FINISH\n");
}
return 0;
}