C++2021年8月月赛题解（Div.2

C++2021年8月月赛题解（Div.2

C++2021年8月Div.2初中组竞赛题解集，全是干货!!!

放置拼块

代码：

# include<cstdio>
# include<iostream>
typedef unsigned long long ull;
using namespace std;
int n, m, k, x, y, ans; ull tmp;
inline int num(int p, int q) {return p * m + q - m - 1;}
inline ull square(int x, int y) {return (1ull << num(x, y)) | (1ull << num(x + 1, y)) | (1ull << num(x, y + 1)) | (1ull << num(x + 1, y + 1));
}
inline void dfs(int dx, int dy) {if(dx == n) return ;for(register int j = dy; j < m; j++)if(!(tmp & square(dx, j))) {tmp |= square(dx, j);ans++;j >= m - 2 ? dfs(dx + 1, 1) : dfs(dx, j + 2);tmp ^= square(dx, j);}for(register int i = dx + 1; i < n; i++)for(register int j = 1; j < m; j++)if(!(tmp & square(i, j))) {tmp |= square(i, j);ans++;j >= m - 2 ? dfs(i + 1, 1) : dfs(i, j + 2);tmp ^= square(i, j);}
}
int main() {scanf("%d%d%d", &n, &m, &k);for(register int i = 1; i <= k; i++)scanf("%d%d", &x, &y), tmp |= square(x, y);dfs(1, 1);printf("%d", ans + 1);return 0;
}

感应门

代码：

# include<cstdio>
# include<iostream>
using namespace std;
int n, x, t, ans, last;
int main() {scanf("%d%d%d", &n, &x, &last);for(int i = 2; i <= n; i++) {scanf("%d", &t);ans += min(t - last, x);last = t;}printf("%d", ans + x);return 0;
} 

伙伴

代码：

# include<cstdio>
# include<iostream>
using namespace std;
const int N = 1e6 + 5;
int n, m, x, l[N], r[N];
int main() {scanf("%d%d", &n, &m);int i;for(i = 1; i <= n; i++) {l[i] = i == 1 ? -1 : i - 1;r[i] = i == n ? -1 : i + 1;}for(i = 1; i <= m; i++) {scanf("%d", &x);if(l[x] == -1) printf("* ");else printf("%d ", l[x]), r[l[x]] = r[x];if(r[x] == -1) printf("* ");else printf("%d ", r[x]), l[r[x]] = l[x];puts("");}return 0;
}

跑步

代码：

# include<cstdio>
#include<iostream>
using namespace std;
const int N = 1e5 + 5;
int n, x, f[N][3];
int main() {scanf("%d", &n);for(int i = 1; i <= n; i++) {scanf("%d", &x);f[i][0] = max(f[i - 1][2], f[i - 1][0]) + x;f[i][1] = max(f[i - 1][2], f[i - 1][0]) + 2 * x;f[i][2] = f[i - 1][1];}printf("%d", max(max(f[n][0], f[n][1]), f[n][2]));return 0;
}

希望对您有所帮助！！！