C++2021年8月月赛题解（Div.2-初中组）题解_初二c++竞赛题目

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！！！