2014年百度之星程序设计大赛 - 资格赛

主要是卡了一下 接下来2题还在做 都有思路

1001

考虑全然即可了

#include <cstdio>
#include <cstring>
using namespace std;
int main()
{
	int T;
	scanf("%d", &T);
	while(T--)
	{
		__int64 n, m, v, k;
		scanf("%I64d %I64d %I64d %I64d", &n, &m, &v, &k);
		if(m >= n)
		{
			puts("0");
			continue;
		}
		if(k <= 1 || m <= v || (m-v)*k == m)
		{
			puts("-1");
			continue;
		}
		int sum = 0;
		while(m < n && m >= 0)
		{
			sum++;
			m = (m-v)*k;	
		}
		if(m <= 0 && m < n)
			sum = -1;
		printf("%d\n", sum);
	}
	return 0;
}

 

1002

 

1003

这题错了半天 伤不起 转成字符串搞字典树就错 最后直接位运算&建树就对了

AC代码

#include <cstdio>
#include <cstring>
typedef __int64 LL;
const int maxn = 100010;
const int maxnode = 60000000;
const int sigma_size = 2;
LL a[maxn];
char s[maxn][70];
int ch[maxnode][sigma_size];
LL val[maxnode];
int sz;
void init()
{
	sz = 1;
	memset(ch[0], 0, sizeof(ch[0]));
}

void insert(LL v)
{
	int u = 0;
	for(int i = 31; i >= 0; i--)
	{
		int c = (v&(1<<i)) == 0 ? 0 : 1;
		if(!ch[u][c])
		{
			memset(ch[sz], 0, sizeof(ch[sz]));
			ch[u][c] = sz++;
		}
		u = ch[u][c];
	}
	val[u] = v;
}
void find(LL x)
{
	LL ans = 0;
	int u = 0;
	for(int i = 31; i >= 0; i--)
	{
		int c = (x&(1<<i)) == 0 ? 0 : 1;
		if(ch[u][c^1])
			u = ch[u][c^1];
		else
			u = ch[u][c];
	}
	printf("%I64d\n", val[u]);
}

int main()
{
	int cas = 1;
	int T;
	scanf("%d", &T);
	while(T--)
	{
		init();
		int n, m;
		scanf("%d %d", &n, &m);
		for(int i = 1; i <= n; i++)
		{
			scanf("%I64d", &a[i]);
			insert(a[i]);
		}
		printf("Case #%d:\n", cas++);
		while(m--)
		{
			LL x;
			scanf("%I64d", &x);
			find(x);
		}		
	}
	return 0;
}

 

然后是错误代码

#include <cstdio>
#include <cstring>
const int maxn = 100010;
const int maxnode = 10000000;
const int sigma_size = 2;
__int64 a[maxn];
char s[maxn][70];
int ch[maxnode][sigma_size];
int val[maxnode];
int sz;
void init()
{
    sz = 1;
    memset(ch[0], 0, sizeof(ch[0]));
}

void insert(char *s, __int64 x)
{
    int u = 0, n = 60;
    for(int i = 0; i < 35; i++)
    {
        int c = s[i] - '0';
        if(!ch[u][c])
        {
            memset(ch[sz], 0, sizeof(ch[sz]));
            val[sz] = 0;
            ch[u][c] = sz++;
        }
        u = ch[u][c];
    }
    val[u] = x;
}
void find(char *s)
{
    __int64 ans = 0;
    int u = 0, n = 35;
    for(int i = 0; i < 35; i++)
    {
        int c = s[i] - '0';
        
        if(ch[u][c^1])
        {
            u = ch[u][c^1];
        }
        else
        {
            u = ch[u][c];
        }
    }
        
    printf("%I64d\n", val[u]);
}

int main()
{
    int cas = 1;
    int T;
    scanf("%d", &T);
    while(T--)
    {
        init();
        int n, m;
        scanf("%d %d", &n, &m);
        for(int i = 1; i <= n; i++)
        {
            scanf("%I64d", &a[i]);
            int x = 35;
            __int64 y = a[i];
            s[i][x] = 0;
            while(x--)
            {
                s[i][x] = y % 2 + '0';
                y /= 2;
            }
            insert(s[i], a[i]);
            //puts(s[i]);
        }
        printf("Case #%d:\n", cas++);
        while(m--)
        {
            __int64 y;
            char str[60];
            scanf("%I64d", &y);
            int x = 35;
            str[x] = 0;
            while(x--)
            {
                str[x] = y % 2 + '0';
                y /= 2;
            }
            //puts(str);
            find(str);
        }        
    }
    return 0;
}

 

1004

简单递推一下

每个点能够由它左边过来然后在从这个点向上向下跟新最大值

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn = 110;
const int INF = 9999999;
int dp[maxn][maxn];
int a[maxn][maxn];
bool vis[maxn][maxn][3];

int main()
{
	int cas = 1;
	int T;
	scanf("%d", &T);
	while(T--)
	{
		int n, m;
		scanf("%d %d", &n, &m);
		for(int i = 1; i <= n; i++)
			for(int j = 0; j <= m; j++)
					dp[i][j] = -INF;
		for(int i = 1; i <= n; i++)
			for(int j = 1; j <= m; j++)
				scanf("%d", &a[i][j]);
		dp[1][1] = a[1][1];
		memset(vis, false, sizeof(vis));
		for(int i = 2; i <= n; i++)
			dp[i][1] = dp[i-1][1] + a[i][1];
		for(int i = 1; i < m; i++)
		{
			for(int j = 1; j <= n; j++)
			{
				int temp = dp[j][i] + a[j][i+1];
				dp[j][i+1] = max(dp[j][i+1], temp);
				int temp1 = temp;
				for(int k = j-1; k >= 1; k--)
				{
					temp1 += a[k][i+1];
					dp[k][i+1] = max(dp[k][i+1], temp1);
				}
				int temp2 = temp;
				for(int k = j+1; k <= n; k++)
				{
					temp2 += a[k][i+1];
					dp[k][i+1] = max(dp[k][i+1], temp2);
				}
			}
		}
		printf("Case #%d:\n", cas++);
		printf("%d\n", dp[1][m]);
		
	}
	return 0;
}