A. To My Critics
#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve(){
vector<int> a(3);
for( auto & i : a )
cin >> i;
sort( a.begin(), a.end() );
if( a[2] + a[1] >= 10 ) cout << "YES\n";
else cout << "NO\n";
}
int32_t main() {
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int t;
cin >> t;
while( t -- )
solve();
return 0;
}
B. Ten Words of Wisdom
#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve(){
int n;
cin >> n;
vector<int> a(n+1) , b(n+1);
for( int i = 1 ; i <= n ; i ++ )
cin >> a[i] >> b[i];
int res = -1 , val = -1;
for( int i = 1 ; i <= n ; i ++ ){
if( a[i] > 10 ) continue;
if( b[i] > val ) val = b[i] , res = i;
}
cout << res << "\n";
}
int32_t main() {
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int t;
cin >> t;
while( t -- )
solve();
return 0;
}
C. Word on the Paper
#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve(){
vector<string> g(8);
for( auto & i : g )
cin >> i;
for( const auto & i : g )
for( const auto & j : i )
if( j != '.' ) cout << j;
cout << "\n";
}
int32_t main() {
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int t;
cin >> t;
while( t -- )
solve();
return 0;
}
D. Balanced Round
#include <bits/stdc++.h>
using namespace std;
void solve() {
int n, k;
cin >> n >> k;
vector<int> a(n);
for (auto &i: a)
cin >> i;
sort(a.begin(), a.end());
int res = 0;
for( int i = 0 , last = INT_MIN , cnt = 0; i < n ; i ++ ){
if( a[i] - last <= k ) cnt ++;
else cnt = 1;
res = max( res , cnt );
last = a[i];
}
cout << n - res << "\n";
}
int main() {
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int t;
cin >> t;
while (t--)
solve();
return 0;
}
E. Cardboard for Pictures
\[c=\sum(s+2w)^2=\sum(s^2+4sw+4w^2)\\ 4nw^2+4\sum (s)w+\sum(s^2)-c=0 \]解一元二次方程
import math
def solve():
n, c = map(int, input().split(' '))
s = list(map(int, input().split(' ')))
a = 4 * n
b , c = 0 , - c
for i in s :
b += i
c += i * i
b = b * 4
res = (math.sqrt(b * b - 4 * a * c) - b) // ( 2 * a )
print(int(res))
T = int(input())
while T > 0:
T -= 1
solve()
F. We Were Both Children
枚举陷阱，枚举陷阱的因子统计答案
#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve() {
int n;
cin >> n;
vector<int> a(n + 1);
for (int i = 1, x; i <= n; i++) {
cin >> x;
if (x > n) continue;
a[x]++;
}
int res = 0;
for (int i = 1, cnt = 0; i <= n; i++) {
cnt = 0;
for (int j = 1; j * j <= i; j++) {
if (i % j != 0) continue;
cnt += a[j];
if (j != i / j)
cnt += a[i / j];
}
res = max(res, cnt);
}
cout << res << "\n";
}
int32_t main() {
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int t;
cin >> t;
while (t--)
solve();
return 0;
}
G. The Morning Star
统计每一行、每一列、每一主对角线、每一负对角线上的点的数量，然后组合数即可
#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve() {
int n;
cin >> n;
map<int,int> a , b , c , d;
for( int x , y ; n ; n -- ){
cin >> x >> y;
a[x] ++ , b[y] ++ , c[x+y] ++ , d[x-y] ++;
}
int res = 0;
for( auto [k,v] : a )
res += v * (v-1) ;
for( auto [k,v] : b )
res += v * (v-1);
for( auto [k,v] : c )
res += v * (v-1);
for( auto [k,v] : d )
res += v * (v-1);
cout << res << "\n";
}
int32_t main() {
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int t;
cin >> t;
while (t--)
solve();
return 0;
}
H. The Third Letter
建无向图，然后任意确定一个点，按照图的顺序去确定其他点的位置，在确定点位置的过程中判断是否合法即可。
#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve() {
int n, m;
cin >> n >> m;
vector<vector<pair<int, int>>> g(n + 1);
for (int i = 1, a, b, c; i <= m; i++) {
cin >> a >> b >> c;
g[a].emplace_back(b, c);
g[b].emplace_back(a, -c);
}
vector<int> d(n + 1, LLONG_MIN);
for (int i = 1; i <= n; i++) {
if( d[i] != LLONG_MIN ) continue;
d[i] = 0;
queue<int> q;
q.push(i);
while (!q.empty()) {
int a = q.front();
q.pop();
for (auto [b, c]: g[a]) {
if (d[b] != LLONG_MIN) {
if (d[b] != d[a] + c) {
cout << "NO\n";
return;
}
} else {
d[b] = d[a] + c;
q.push(b);
}
}
}
}
cout << "YES\n";
}
int32_t main() {
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
int t;
cin >> t;
while (t--)
solve();
return 0;
}