Merge pull request #20 from AlgoLeadMe/6-rivkms

6-rivkms

Author: rivkms

rivkms/BFS/7576.cpp

@@ -0,0 +1,68 @@
+#include <iostream>
+#include <vector>
+#include <queue>
+
+using namespace std;
+int SIZE;
+
+int main(){
+    ios_base::sync_with_stdio(false);
+	cin.tie(NULL);
+    int w, h, s = 0;
+    cin >> w >> h;
+    SIZE = w*h;
+    
+    vector<int> box(SIZE);
+    queue<int> q;
+
+    for(int i = 0; i<SIZE; i++){
+        cin >> box[i];
+        if(box[i]==1){
+            q.push(i);
+        }
+    }
+    q.push(-1);
+    while(!q.empty()){
+        int tmp = q.front();
+        q.pop();
+        if(tmp == -1){
+            if(q.empty()){
+                break;
+            }
+            s++;
+            q.push(-1);
+            continue;
+        }
+        int x = tmp%w;
+        int y = tmp/w;
+        for(int i = 0; i<4; i++){
+            if(x+1<w && box[y*w+x+1]==0){
+                box[y*w+x+1] = 1;
+                q.push(y*w+x+1);
+            }
+            else if(y+1<h&&box[(y+1)*w+x]==0){
+                box[(y+1)*w+x] = 1;
+                q.push((y+1)*w+x);
+            }
+            else if(x>0 && box[y*w+x-1]==0){
+                box[y*w+x-1] = 1;
+                q.push(y*w+x-1);
+            }
+            else if(y>0 && box[(y-1)*w+x]==0){
+                box[(y-1)*w+x] = 1;
+                q.push((y-1)*w+x);
+            }
+        }
+    }
+    for(int y = 0; y<h; y++){
+        for(int x = 0; x<w; x++){
+            if(box[y*w+x]==0){
+                cout << -1;
+                return 0;
+            }
+        }
+    }
+    cout << s;
+
+    return 0;
+}

rivkms/BFS/7576_2.cpp

@@ -0,0 +1,59 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+int SIZE;
+bool filled(const vector<int>& box){
+    for(int i = 0; i<SIZE; i++){
+        if(box[i]==0){
+            return false;
+        }
+    }
+    return true;
+}
+
+bool changed(const vector<int>& box1, const vector<int>& box2){
+    for(int i = 0; i<SIZE; i++){
+        if(box1[i]!=box2[i]){
+            return true;
+        }
+    }
+    return false;
+}
+
+int main(){
+    ios_base::sync_with_stdio(false);
+	cin.tie(NULL);
+    int w, h, s = 0;
+    cin >> w >> h;
+    SIZE = w*h;
+    vector<int> box(SIZE);
+    vector<int> box2(SIZE, 0);
+    for(int i = 0; i<SIZE; i++){
+        cin >> box[i];
+    }
+    while(true){
+        if(filled(box)){
+            cout << s << endl;
+            break;
+        }
+
+        s++;
+        for(int y = 0; y<h; y++){
+            for(int x = 0 ; x<w; x++){
+                if(box[y*w+x]<0) box2[y*w+x] = -1;
+                else if(box[y*w+x]>0) box2[y*w+x] = 1;
+                else if(x>0 && box[y*w+x-1]>0) box2[y*w+x] = 1;
+                else if(y>0 && box[(y-1)*w+x]>0) box2[y*w+x] = 1;
+                else if(x<w-1 && box[y*w+x+1]>0) box2[y*w+x] = 1;
+                else if(y<h-1 && box[(y+1)*w+x]>0) box2[y*w+x] = 1;
+            }
+        }
+
+        if(!changed(box, box2)){
+            cout << -1 << endl;
+            break;
+        }
+        box = box2;
+    }
+}

rivkms/Backtracking/31413.cpp

@@ -7,35 +7,35 @@ using namespace std;
 int N, M, A, D;
 vector<int> vec;
 pair<int, int> compare(const pair<int, int>& p1, const pair<int, int>& p2) {
-    if (p1.second > p2.second) {
-        if (p2.first >= M) {
+    if(p1.first < M){
+        if(p2.first < M){
+            return p1.second < p2.second ? p1 : p2;
+        }
+        else{
             return p2;
         }
-        return p1;
     }
-    if (p1.second < p2.second) {
-        if (p1.first >= M) {
+    else{
+        if(p2.first < M){
             return p1;
         }
-        return p2;
+        else{
+            return p1.second < p2.second ? p1 : p2;
+        }
     }
-    return p1.first > p2.first ? p1 : p2;
 }
 
-pair<int, int> dfs(bool blood, int point, int num, int n) {
+pair<int, int> dfs(int point, int num, int n, int canblood) {
     if (n == N) {
         return pair<int, int>(point, num);
     }
-    if (!blood) {
-        point += vec[n];
-        pair<int, int> p1 = dfs(false, point, num, n + 1);
-        pair<int, int> p2 = dfs(true, point, num, n + 1);
+    if(!canblood){
+        pair<int, int> p1 = dfs(point+vec[n], num, n + 1, canblood);
+        pair<int, int> p2 = dfs(point+A, num+1, n + 1, D-1);
         return compare(p1, p2);
     }
-    else {
-        point += A;
-        num += D;
-        return dfs(false, point, num, n + 1);
+    else{
+        return dfs(point, num, n + 1, canblood-1);
     }
 }
 
@@ -46,14 +46,11 @@ int main() {
         cin >> tmp;
         vec.push_back(tmp);
     }
+
     cin >> A >> D;
 
-    pair<int, int> p = dfs(false, 0, 0, 0);
-    if (p.first >= M) {
-        cout << -1;
-    }
-    else {
-        cout << p.second;
-    }
+    pair<int, int> p = dfs(0, 0, 0, 0);
+    cout<< p.first << " " << p.second;
+
     return 0;
 }

rivkms/README.md

@@ -6,5 +6,6 @@
 | 2차시 | 2024.02.15 |  Recursion  | [하노이 탑 이동 순서](https://www.acmicpc.net/problem/11729)  | [#2](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/8) |
 | 3차시 | 2024.02.18 |  DP  | [하노이 탑 이동 순서](https://www.acmicpc.net/problem/10844)  | [#3](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/11) |
 | 4차시 | 2024.02.18 |  Backtracking  | [N-queen](https://www.acmicpc.net/problem/9663)  | [#4](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/13) |
-| 5차시 | 2024.02.24 |  Backtracking  | [입대](https://www.acmicpc.net/problem/31413)  | [#5](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/18) |
+| 5차시 | 2024.02.24 | Backtracking | [입대](https://www.acmicpc.net/problem/31413) | [#5](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/18) |
+| 6차시 | 2024.02.27 | BFS | [토마토](https://www.acmicpc.net/problem/7576) | [#6](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/20) |
 ---