[20250708] BOJ / D5 / 택배 배달 / 권혁준

khj20006/202507/08 BOJ D5 택배 배달.md

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+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+using ll = long long;
+
+ll A[2001][201]{}, S[2001][201]{};
+ll le[2001]{}, ri[2001]{};
+ll dist[2001][2001]{}, up[2001][2001]{}, down[2001][2001]{}, mid[2001][2001]{};
+pair<int, int> p[200002]{};
+
+int main(){
+    cin.tie(0)->sync_with_stdio(0);
+
+    int R, C;
+    cin>>R>>C;
+
+    for(int i=1;i<=R;i++) {
+        for(int j=1;j<=C;j++) {
+            cin>>A[i][j];
+            S[i][j] = S[i][j-1] + A[i][j];
+        }
+        le[i] = le[i-1] + A[i][1];
+        ri[i] = ri[i-1] + A[i][C];
+    }
+
+    for(int j=1;j<=R;j++) {
+        up[1][j] = S[1][C] + ri[j]-ri[1];
+        up[j][1] = S[1][C] + le[j]-le[1];
+    }
+    for(int i=2;i<=R;i++) for(int j=2;j<=R;j++) {
+        up[i][j] = min(up[i-1][j] + A[i][1], up[i][j-1] + A[j][C]);
+        if(i<j) {
+            up[i][j] = min(up[i][j], S[i][C] + ri[j]-ri[i]);
+        }
+        else{
+            up[i][j] = min(up[i][j], S[j][C] + le[i]-le[j]);
+        }
+    }
+
+    for(int j=1;j<=R;j++) {
+        down[R][j] = S[R][C] + ri[R-1]-ri[j-1];
+        down[j][R] = S[R][C] + le[R-1]-le[j-1];
+    }
+    for(int i=R-1;i>=1;i--) for(int j=R-1;j>=1;j--) {
+        down[i][j] = min(down[i+1][j] + A[i][1], down[i][j+1] + A[j][C]);
+        if(i<j) {
+            down[i][j] = min(down[i][j], S[j][C] + le[j-1]-le[i-1]);
+        }
+        else{
+            down[i][j] = min(down[i][j], S[i][C] + ri[i-1]-ri[j-1]);
+        }
+    }
+
+    for(int i=1;i<=R;i++) mid[i][i] = S[i][C];
+    for(int k=1;k<R;k++) for(int i=1;i+k<=R;i++) {
+        int j = i+k;
+        mid[i][j] = min({mid[i+1][j] + A[i][1], mid[i][j-1] + A[j][C], S[i][C] + ri[j]-ri[i], S[j][C] + le[j-1]-le[i-1]});
+        mid[j][i] = min({mid[j-1][i] + A[j][1], mid[j][i+1] + A[i][C], S[i][C] + le[j]-le[i], S[j][C] + ri[j-1]-ri[i-1]});
+    }
+
+    for(int i=1;i<=R;i++) for(int j=1;j<=R;j++) {
+        dist[i][j] = min({up[i][j], down[i][j], mid[i][j]});
+    }
+
+    p[0] = {1,1};
+    int D;
+    cin>>D;
+    for(int i=1;i<=D;i++) cin>>p[i].first>>p[i].second;
+
+    ll ans = A[1][1];
+    for(int i=1;i<=D;i++) {
+        auto [pr,pc] = p[i-1];
+        auto [r,c] = p[i];
+
+        if(pr == r) {
+            if(pc < c) {
+                ll res1 = S[r][c] - S[r][pc];
+                ll res2 = dist[r][r] + max(0LL, S[r][C-1]-S[r][c-1]);
+                if(pc == 1) res2 -= A[pr][1];
+                else res2 += S[pr][pc-1]-S[pr][1];
+                ans += min(res1, res2);
+            }
+            else{
+                ll res1 = S[r][pc-1] - S[r][c-1];
+                ll res2 = dist[r][r] + max(0LL, S[r][c]-S[r][1]);
+                if(pc == C) res2 -= A[pr][C];
+                else res2 += S[pr][C-1]-S[pr][pc];
+                ans += min(res1, res2);
+            }
+        }
+        else {
+            // prev에서 왼쪽으로, cur에서 오른쪽으로
+            ll res1 = dist[pr][r] + max(0LL, S[r][C-1]-S[r][c-1]);
+            if(pc == 1) res1 -= A[pr][1];
+            else res1 += S[pr][pc-1]-S[pr][1];
+            // prev에서 오른쪽으로, cur에서 왼쪽으로
+            ll res2 = dist[r][pr] + max(0LL, S[r][c]-S[r][1]);
+            if(pc == C) res2 -= A[pr][C];
+            else res2 += S[pr][C-1]-S[pr][pc];
+            // prev에서 왼쪽으로, cur에서 왼쪽으로
+            ll res3 = (pr<r ? le[r-1]-le[pr] : le[pr-1]-le[r]) + S[pr][pc-1] + S[r][c];
+            // prev에서 오른쪽으로, cur에서 오른쪽으로
+            ll res4 = (pr<r ? ri[r-1]-ri[pr] : ri[pr-1]-ri[r]) + S[pr][C]-S[pr][pc] + S[r][C]-S[r][c-1];
+
+            ll res = min({res1, res2, res3, res4});
+
+            ans += res;
+        }
+
+    }
+    cout<<ans;
+
+}
+```