标签：typedef ch int long while 卡常 getchar

事情起因

2023.2.4模拟赛, T3

该题当时考场上真的想不出来什么正解,于是就开始打暴力

第一次提交

结果如下图

代码:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;

inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while(ch < '0' || ch > '9')
    {
        if(ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
    {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}

const int N = 5e5 + 10;
int a[N];
int n, m, t;

int find(int len)
{
    int l, cnt = 0;
    for(int i = 1; i <= n; i ++ )
    {
        if(a[i] == 1) cnt = 0;
        if(!cnt && a[i] == 0) l = i;
        if(a[i] == 0) cnt ++;
        if(cnt == len) return l;
    }
    return 0;
}

int main()
{
    #ifdef LOCAL
        freopen("in.in", "r", stdin);
        freopen("out.out", "w", stdout);
    #endif

    n = read(), m = read();

    while(m -- )
    {
        int op = read(), x = read(), y;
        if(op == 1)
        {
            int l = find(x);
            if(l != 0)
                for(int i = l; i <= l + x - 1; i ++ )
                    a[i] = 1;
                    
            cout << l << endl;
        }
        else
        {
            y = read();
            for(int i = x; i < x + y; i ++ )
                a[i] = 0;
        }
    }
    
    return 0;
}

PS: 本人有加快读的习惯

只拿了一半分(说实话我也没想到能拿一半分)

改代码

拿了一半分可不行(确信)

然后我就开始着力改一些细节

首先把所有的for循环中加入register, 函数前加上inline

于是代码变成了

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;

inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while(ch < '0' || ch > '9')
    {
        if(ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
    {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}

const int N = 5e5 + 10;
int a[N];
int n, m, t;

inline int find(int len)
{
    int l, cnt = 0;
    for(register int i = 1; i <= n; i ++ )
    {
        if(a[i] == 1) cnt = 0;
        if(!cnt && a[i] == 0) l = i;
        if(a[i] == 0) cnt ++;
        if(cnt == len) return l;
    }
    return 0;
}

int main()
{
    #ifdef LOCAL
        freopen("in.in", "r", stdin);
        freopen("out.out", "w", stdout);
    #endif

    n = read(), m = read();

    while(m -- )
    {
        int op = read(), x = read(), y;
        if(op == 1)
        {
            int l = find(x);
            if(l != 0)
                for(register int i = l; i <= l + x - 1; i ++ )
                    a[i] = 1;
                    
            cout << l << endl;
        }
        else
        {
            y = read();
            for(register int i = x; i < x + y; i ++ )
                a[i] = 0;
        }
    }
    
    return 0;
}

分数+8

我狂喜直接(bushi)

但还是没拿更高的分(真贪啊)

接着改

改了一些小地方, 比如什么

int a = read()变成了int a(read())

i ++变为++ i

改cout为printf

但是还是过不了别的点

然后进行了一些位运算优化

比如把x == y改为!(x ^ y)这种异或

最终

又2个点!

直接干到82分

代码

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;

inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while(ch < '0' || ch > '9')
    {
        if(ch == '-') f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
    {
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return x * f;
}

inline void write(int x)
{
    if(x<0){
    	putchar('-');
		x=-x;
	}
    if(x>9) write(x/10);
    putchar(x%10+'0');
}

const int N = 5e4 + 9;
int a[N];
int n, m, t;

inline int find(int len)
{
    int l, cnt = 0;
    for(register int i(1); i <= n; ++ i )
    {
        if(a[i]) cnt = 0;
        if(!cnt && !a[i]) l = i;
        if(!a[i]) cnt ++;
        if(!(cnt ^ len)) return l;
    }
    return 0;
}

int main()
{
    #ifdef LOCAL
        freopen("in.in", "r", stdin);
        freopen("out.out", "w", stdout);
    #endif

    n = read(), m = read();

    while(m -- )
    {
        int op(read()), x(read()), y;
        if(!(op ^ 1))
        {
            int l(find(x));
            if(l)
                for(register int i(l); i <= l + x - 1; ++ i )
                    a[i] = 1;
                    
            printf("%d\n", l);
        }
        else
        {
            y = read();
            int t(x + y);
            for(register int i(x); i < t; ++ i )
                a[i] = 0;
        }
    }
    
    return 0;
}

还没完

在写这篇的时候, 我突然想到LYT昨晚说的:

O2跑的飞快

然后我就去测试了下

????????????

直接起飞了就

(怪不得考试不加O2)

标签：typedef,ch,int,long,while,卡常,getchar
From： https://www.cnblogs.com/crimsonawa/p/17093535.html