CF 797, got stuck on E and had to leave, went pretty well

codeforces/rounds/797/a.cpp

@@ -0,0 +1,38 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void test_case(int tc){
+    int n;
+    cin >> n;
+
+    int result = n / 3 + 2;
+    if(n % 3 == 0) {
+        result = n / 3 + 1;
+    }
+    int r2 = result - 1;
+    if(n == 7){
+        r2 = 2;
+    }
+    int lowest = n - result - r2;
+
+    cout << r2 << " " << result << " " << lowest << '\n';
+}
+
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    for(int tc = 1; tc <= t; ++tc){
+        test_case(tc);
+    }
+
+    cout << flush;
+
+    return 0;
+}

codeforces/rounds/797/b.cpp

@@ -0,0 +1,66 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void test_case(int tc){
+    int n;
+    cin >> n;
+
+    vector<int> a(n);
+    vector<int> b(n);
+
+    for (size_t i = 0; i < n; i++){
+        cin >> a[i];
+    }
+
+    for (size_t i = 0; i < n; i++){
+        cin >> b[i];
+    }
+
+    bool result = true;
+
+    int exactdif = INT32_MAX;
+    int hightestdif = 0;
+    bool onlyzeroes = true;
+
+    for(size_t i = 0; i < n; ++i){
+        auto ax = a[i], bx = b[i];
+        auto d = ax - bx;
+
+        if(bx == 0){
+            hightestdif = max(hightestdif, d);
+        } else {
+            onlyzeroes = false;
+            if(exactdif == INT32_MAX){
+                exactdif = d;
+            } else if(exactdif != d){
+                result = false;
+                break;
+            }
+        }
+    }
+
+    if(hightestdif > exactdif){
+        result = false;
+    }
+    
+    cout << (result || onlyzeroes ? "YES" : "NO") << '\n';
+}
+
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    for(int tc = 1; tc <= t; ++tc){
+        test_case(tc);
+    }
+
+    cout << flush;
+
+    return 0;
+}

codeforces/rounds/797/c.cpp

@@ -0,0 +1,48 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+typedef unsigned long long ull;
+
+void test_case(int tc){
+    int n;
+    cin >> n;
+
+    vector<int> s(n);
+    vector<int> f(n);
+
+    for(size_t i = 0; i < n; ++i){
+        cin >> s[i];
+    }
+
+    for(size_t i = 0; i < n; ++i){
+        cin >> f[i];
+
+        if(i != 0){
+            cout << f[i] - max(s[i], f[i-1]) << " ";
+        } else {
+            cout << f[i] - s[i] << " ";
+        }
+    }
+
+    cout << "\n";
+
+}
+
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    for(int tc = 1; tc <= t; ++tc){
+        test_case(tc);
+    }
+
+    cout << flush;
+
+    return 0;
+}

codeforces/rounds/797/d.cpp

@@ -0,0 +1,68 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void test_case(int tc){
+    int n, k;
+    cin >> n >> k;
+
+    vector<bool> strip;
+
+    int blacks = 0;
+    int whites = 0;
+    for(int i = 0; i < k; ++i){
+        char c;
+        cin >> c;
+
+        if(c == 'B'){
+            blacks++;
+            strip.push_back(true);
+        } else{
+            whites++;
+            strip.push_back(false);
+        }
+    }
+
+    int min_whites = whites;
+
+    for(int i = 0; i < n - k; ++i){
+        char c;
+        cin >> c;
+
+        if(strip[i]){
+            blacks--;
+        } else {
+            whites--;
+        }
+
+        if(c == 'B'){
+            blacks++;
+            strip.push_back(true);
+        } else {
+            whites++;
+            strip.push_back(false);
+        }
+
+        min_whites = min(min_whites, whites);
+    }
+
+    cout << min_whites << '\n';
+}
+
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    for(int tc = 1; tc <= t; ++tc){
+        test_case(tc);
+    }
+
+    cout << flush;
+
+    return 0;
+}

codeforces/rounds/797/e.cpp

@@ -0,0 +1,76 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void test_case(int tc){
+    int n, k;
+
+    cin >> n >> k;
+
+    vector<vector<int>> modulos(k);
+
+    for(int i = 0; i < n; ++i){
+        int s;
+        cin >> s;
+
+        modulos[s % k].push_back(s);
+    }
+
+    for(auto v : modulos){
+        sort(v.begin(), v.end());
+    }
+
+    unsigned long long result = 0;
+
+    for(int i = k - 1; i > 0; i--){
+        while(!modulos[i].empty() && !modulos[k-i].empty()){
+            int a = modulos[i].back(), b = modulos[k - 1].back();
+            modulos[i].pop_back();
+            modulos[k-1].pop_back();
+
+            result += (a + b) / k;
+        }
+    }
+
+    while(modulos[0].size() > 1){
+        int a = modulos[0].back();
+        modulos[0].pop_back();
+        int b = modulos[0].back();
+        modulos[0].pop_back();
+
+        result += (a + b) / k;
+    }
+
+    for(int i = 0; i < k; ++i){
+        for(int j = i + 1; j < k; ++j){
+            while(!modulos[i].empty() && !modulos[j].empty()){
+                int a = modulos[i].back(), b = modulos[j].back();
+                modulos[i].pop_back();
+                modulos[j].pop_back();
+
+                result += (a + b) / k;
+            }
+        }
+    }
+
+    cout << result << '\n';
+
+}
+
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    for(int tc = 1; tc <= t; ++tc){
+        test_case(tc);
+    }
+
+    cout << flush;
+
+    return 0;
+}

codeforces/rounds/797/f.cpp

@@ -0,0 +1,25 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void test_case(int tc){
+
+}
+
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    for(int tc = 1; tc <= t; ++tc){
+        test_case(tc);
+    }
+
+    cout << flush;
+
+    return 0;
+}

codeforces/rounds/797/g.cpp

@@ -0,0 +1,25 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void test_case(int tc){
+
+}
+
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    for(int tc = 1; tc <= t; ++tc){
+        test_case(tc);
+    }
+
+    cout << flush;
+
+    return 0;
+}