ACM模板

struct fastio{
    char s[100005];
    int it,len;
    fastio(){it=len=0;}
    inline char get(){
        if(it<len)return s[it++];it=0;
        len=fread(s,1,100000,stdin);
        if(len==0)return EOF;else return s[it++];
    }
    bool notend(){
        char c=get();
        while(c==' '||c=='\n')c=get();
        if(it>0)it--;
        return c!=EOF;
    }
}_buff;
#define read(x) x=getnum()
#define write(x) putnum(x),putchar('\n')

inline LL getnum(){
    LL r=0;bool ng=0;char c;c=_buff.get();
    while(c!='-'&&(c<'0'||c>'9'))c=_buff.get();
    if(c=='-')ng=1,c=_buff.get();
    while(c>='0'&&c<='9')r=r*10+c-'0',c=_buff.get();
    return ng?-r:r;
}
template<class T> inline void putnum(T x){
    if(x<0)putchar('-'),x=-x;
    register short a[20]={},sz=0;
    while(x)a[sz++]=x%10,x/=10;
    if(sz==0)putchar('0');
    for(int i=sz-1;i>=0;i--)putchar('0'+a[i]);
}
inline char getreal(){char c=_buff.get();while(c<=32)c=_buff.get();return c;}

常用头文件：

g++ -std=c++14 A.cpp -o A -D LH_LOCAL

/*
**链接**
传送门: [here]()
**题意**
**思路**
**备注**
*/
#pragma comment(linker, "/STACK:102400000,102400000")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize(3,"Ofast","inline")
#pragma GCC optimize("Ofast,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
#define fi first
#define se second
#define o2(x) (x) * (x)
#define mk make_pair
#define eb emplace_back
#define SZ(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define clr(a, b) memset((a), (b), sizeof((a)))
#define rep(i, s, t) for(register int i = (s), LIM=(t); i < LIM; ++i)
#define per(i, s, t) for(register int i = (s), LIM=(t); i >= LIM; --i)
#define GKD std::ios::sync_with_stdio(false);cin.tie(0)
#define my_unique(x) sort(all(x)), x.erase(unique(all(x)), x.end())
using namespace std;
typedef long long LL;
typedef long long int64;
typedef unsigned long long uint64;
typedef pair<int, int> pii;
// mt19937 rng(time(NULL));//std::clock()
// mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
// shuffle(arr, arr + n, rng64);
inline int64 read() {
    int64 x = 0;int f = 0;char ch = getchar();
    while (ch < '0' || ch > '9') f |= (ch == '-'), ch = getchar();
    while (ch >= '0' && ch <= '9') x = (x << 3) + (x << 1) + ch - '0', ch =
    getchar(); return x = f ? -x : x;
}
inline void write(int64 x, bool f = true) {
    if (x == 0) {putchar('0'); if(f)putchar('\n');else putchar(' ');return;}
    if (x < 0) {putchar('-');x = -x;}
    static char s[23];
    int l = 0;
    while (x != 0)s[l++] = x % 10 + 48, x /= 10;
    while (l)putchar(s[--l]);
    if(f)putchar('\n');else putchar(' ');
}
int lowbit(int x) { return x & (-x); }
template <class T>
T big(const T &a1, const T &a2) {return a1 > a2 ? a1 : a2;}
template <class T>
T sml(const T &a1, const T &a2) {return a1 < a2 ? a1 : a2;}
template <typename T, typename... R>
T big(const T &f, const R &... r) {return big(f, big(r...));}
template <typename T, typename... R>
T sml(const T &f, const R &... r) {return sml(f, sml(r...));}
void debug_out() { cout << '\n'; }
template <typename T, typename... R>
void debug_out(const T &f, const R &... r) {
    cout << f << " ";
    debug_out(r...);
}
#ifdef LH_LOCAL
#define debug(...) cout << "[" << #__VA_ARGS__ << "]: ", debug_out(__VA_ARGS__);
#else
#define debug(...) ;
#endif
/*================Header Template==============*/
const int mod = 998244353;// 998244353
const int INF = 0x3f3f3f3f;
int ksm(int a, int64 b, int kmod = mod) {int res = 1;for(;b > 0;b >>= 1, a = (int64)a * a % kmod) if(b &1) res = (int64)res * a % kmod;return res;}
const int MXN = 2e5 + 5;

int n, m;
void work() {
    n = read();
}
int main() {
#ifdef LH_LOCAL
    freopen("D:/ACM/mtxt/in.txt", "r", stdin);
    // freopen("D:/ACM/mtxt/out.txt", "w", stdout);
#endif
    for(int cas = 1, tim = 1; cas <= tim; ++ cas) {
        // printf("Case #%d:\n", cas);
        work();
    }
#ifdef LH_LOCAL
    cout << "time cost:" << 1.0 * clock() / CLOCKS_PER_SEC << "s" << endl;
#endif
    return 0;
}

vscode snippets

{
	// Place your snippets for cpp here. Each snippet is defined under a snippet name and has a prefix, body and 
	// description. The prefix is what is used to trigger the snippet and the body will be expanded and inserted. Possible variables are:
	// $1, $2 for tab stops, $0 for the final cursor position, and ${1:label}, ${2:another} for placeholders. Placeholders with the 
	// same ids are connected.
	// Example:
	// "Print to console": {
	// 	"prefix": "log",
	// 	"body": [
	// 		"console.log('$1');",
	// 		"$2"
	// 	],
	// 	"description": "Log output to console"
	// },
	"简单线段树模板": {
		"prefix": "mb_seg1",
		"body": [
			"class SegT1 {",
"    public:",
"#define lson rt << 1",
"#define rson rt << 1 | 1",
"    int N;",
"    vector<int> lazy;",
"    vector<int64_t> sum;",
"    SegT1(int N = 0) : N(N), lazy((N << 2) + 5), sum((N << 2) + 5) {}",
"    void pop(int rt) {",
"        sum[rt] = (sum[lson] + sum[rson]);",
"    }",
"    void build(int l, int r, int rt) {",
"        lazy[rt] = 0;",
"        if(l == r) {",
"            sum[rt] = 1;",
"            return ;",
"        }",
"        int mid = (l + r) >> 1;",
"        build(l, mid, lson), build(mid + 1, r, rson);",
"        pop(rt);",
"    }",
"    void push(int rt, int l, int r) {",
"        if(lazy[rt] == 0) return ;",
"        int mid = (l + r) >> 1;",
"        lazy[lson] += lazy[rt];",
"        lazy[rson] += lazy[rt];",
"        sum[lson] += lazy[rt] * (mid - l + 1);",
"        sum[rson] += lazy[rt] * (r - mid);",
"        lazy[rt] = 0;",
"    }",
"    void apply(int rt, int l, int r, int v) {",
"        lazy[rt] += v;",
"        sum[rt] += v * (r - l + 1);",
"    }",
"    void update(int v, int L, int R, int l, int r, int rt) {",
"        if(L <= l && r <= R) {",
"            apply(rt, l, r, v);",
"            return ;",
"        }",
"        int mid = (l + r) >> 1;",
"        push(rt, l, r);",
"        if(L > mid) {update(v, L, R, mid + 1, r, rson);}",
"        else if(R <= mid) {update(v, L, R, l, mid, lson);}",
"        else {",
"            update(v, L, mid, l, mid, lson);",
"            update(v, mid + 1, R, mid + 1, r, rson);",
"        }",
"        pop(rt);",
"    }",
"    int query(int L, int R, int l, int r, int rt) {",
"        if(L <= l && r <= R) {",
"            return sum[rt];",
"        }",
"        int mid = (l + r) >> 1, ans = 0;",
"        push(rt, l, r);",
"        if(L > mid) {ans += query(L, R, mid + 1, r, rson);}",
"        else if(R <= mid) {ans += query(L, R, l, mid, lson);}",
"        else {",
"            ans += query(L, mid, l, mid, lson);",
"            ans + query(mid + 1, R, mid + 1, r, rson);",
"        }",
"        return ans;",
"        pop(rt);",
"    }",
"#undef lson",
"#undef rson",
"};",
		],
		"description": "简单线段树模板"
	},
	"freopen模板": {
		"prefix": "mb_freopen",
		"body": [
			"#ifdef LH_LOCAL",
"    freopen(\"D:/ACM/mtxt/in.txt\", \"r\", stdin);",
"    // freopen(\"D:/ACM/mtxt/out.txt\", \"w\", stdout);",
"#endif",
		],
		"description": "freopen模板"
	},
	"头文件完整": {
		"prefix": "mb_headfile1",
		"body": [
			"#include <bits/stdc++.h>",
"#define fi first",
"#define se second",
"#define o2(x) (x) * (x)",
"#define mk make_pair",
"#define eb emplace_back",
"#define SZ(x) ((int)(x).size())",
"#define all(x) (x).begin(), (x).end()",
"#define clr(a, b) memset((a), (b), sizeof((a)))",
"#define rep(i, s, t) for(register int i = (s), LIM=(t); i < LIM; ++i)",
"#define per(i, s, t) for(register int i = (s), LIM=(t); i >= LIM; --i)",
"#define GKD std::ios::sync_with_stdio(false);cin.tie(0)",
"#define my_unique(x) sort(all(x)), x.erase(unique(all(x)), x.end())",
"using namespace std;",
"typedef long long LL;",
"typedef long long int64;",
"typedef unsigned long long uint64;",
"typedef pair<int, int> pii;",
"// mt19937 rng(time(NULL));//std::clock()",
"// mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());",
"// shuffle(arr, arr + n, rng64);",
"inline int64 read() {",
"    int64 x = 0;int f = 0;char ch = getchar();",
"    while (ch < '0' || ch > '9') f |= (ch == '-'), ch = getchar();",
"    while (ch >= '0' && ch <= '9') x = (x << 3) + (x << 1) + ch - '0', ch =",
"    getchar(); return x = f ? -x : x;",
"}",
"inline void write(int64 x, bool f = true) {",
"    if (x == 0) {putchar('0'); if(f)putchar('\\n');else putchar(' ');return;}",
"    if (x < 0) {putchar('-');x = -x;}",
"    static char s[23];",
"    int l = 0;",
"    while (x != 0)s[l++] = x % 10 + 48, x /= 10;",
"    while (l)putchar(s[--l]);",
"    if(f)putchar('\\n');else putchar(' ');",
"}",
"int lowbit(int x) { return x & (-x); }",
"template <class T>",
"T big(const T &a1, const T &a2) {return a1 > a2 ? a1 : a2;}",
"template <class T>",
"T sml(const T &a1, const T &a2) {return a1 < a2 ? a1 : a2;}",
"template <typename T, typename... R>",
"T big(const T &f, const R &... r) {return big(f, big(r...));}",
"template <typename T, typename... R>",
"T sml(const T &f, const R &... r) {return sml(f, sml(r...));}",
"void debug_out() { cout << '\\n'; }",
"template <typename T, typename... R>",
"void debug_out(const T &f, const R &... r) {",
"    cout << f << \" \";",
"    debug_out(r...);",
"}",
"#ifdef LH_LOCAL",
"#define debug(...) cout << \"[\" << #__VA_ARGS__ << \"]: \", debug_out(__VA_ARGS__);",
"#else",
"#define debug(...) ;",
"#endif",
"/*================Header Template==============*/",
"const int mod = 998244353;// 998244353",
"const int INF = 0x3f3f3f3f;",
"int ksm(int a, int64 b, int kmod = mod) {int res = 1;for(;b > 0;b >>= 1, a = (int64)a * a % kmod) if(b &1) res = (int64)res * a % kmod;return res;}",
"const int MXN = 2e5 + 5;",
"",
"int n, m;",
"void work() {",
"    n = read();",
"}",
"int main() {",
"#ifdef LH_LOCAL",
"    freopen(\"D:/ACM/mtxt/in.txt\", \"r\", stdin);",
"    // freopen(\"D:/ACM/mtxt/out.txt\", \"w\", stdout);",
"#endif",
"    for(int cas = 1, tim = 1; cas <= tim; ++ cas) {",
"        // printf(\"Case #%d:\\n\", cas);",
"        work();",
"    }",
"#ifdef LH_LOCAL",
"    cout << \"time cost:\" << 1.0 * clock() / CLOCKS_PER_SEC << \"s\" << endl;",
"#endif",
"    return 0;",
"}",
		],
		"description": "头文件完整"
	},
	"头文件部分": {
		"prefix": "mb_headfile2",
		"body": [
			"#include <bits/stdc++.h>",
"using namespace std;",
"void debug_out() { cout << '\\n'; }",
"template <typename T, typename... R>",
"void debug_out(const T &f, const R &... r) {",
"    cout << f << \" \";",
"    debug_out(r...);",
"}",
"#ifndef ONLINE_JUDGE",
"#define debug(...) cout << \"[\" << #__VA_ARGS__ << \"]: \", debug_out(__VA_ARGS__);",
"#else",
"#define debug(...) ;",
"#endif",
"typedef long long LL;",
"bool Finish_read;",
"inline long long Rd() {long long x = 0;Finish_read = 0;int f = 1;char ch = getchar();while (!isdigit(ch)) {if (ch == '-') f = -1;if (ch == EOF) return x;ch = getchar();}while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();x *= f;Finish_read = 1;return x;}",
"template <class T>inline void print(T x) {if(x > 9) print(x / 10), putchar(x % 10 ^ 48);else if(x < 0) putchar('-'), print(-x);else putchar(x % 10 ^ 48);}",
"template <class T>inline void write(T x, char c = '\\n') {print(x);putchar(c);}",
"#define read(x) x = Rd()",
"#define read2(x, y) x = Rd(), y = Rd()",
"#define read3(x, y, z) x = Rd(), y = Rd(), z = Rd()",
"",
"constexpr int mod = 998244353;",
"constexpr int INF = 0x3f3f3f3f;",
"constexpr int mxN = 2e5 + 5;",
"int n, m;",
"int ans;",
"void prework() {",
"    read(n);",
"    debug(n)",
"}",
"void work() {",
"    ",
"}",
"void finalwork() {",
"    write(n);",
"}",
"int main() {",
"    for(int Case = 1, allc = 1; Case <= allc; ++ Case) {",
"        prework();",
"        work();",
"        finalwork();",
"    }",
"    return 0;",
"}",
		],
		"description": "头文件部分"
	},
}