C++ vector::PB方法代码示例

void solve(){
  for( int i = 0 ; i < n ; i ++ )
    if( c[ i ] == '<' ){
      if( c[ i + 1 ] == '/' ){
        if( c[ i + 2 ] == 'U' ) i += 4;
        else i += 6;
        v.pop_back();
      }else if( c[ i + 1 ] == 'U' ) v.PB( 1 ) , i += 3;
      else v.PB( 2 ) , i += 5;
    }else{
      if( v.size() && v.back() == 1 ) putchar( toC( c[ i ] ) );
      else if( v.size() && v.back() == 2 ) putchar( toS( c[ i ] ) );
      else putchar( c[ i ] );
    }
  puts( "" );
}

int main() {

	while (~scanf("%d", &n)) {
		map<int, int> idx;
		ed.clear();
		int m = 0;
		for (int i = 0; i < n; i++) {
			int a, b, r, p;
			scanf("%d%d%d%d", &a, &b, &r, &p);
			if (idx.find(a) == idx.end()) {
				idx[a] = ++m;
			}
			if (idx.find(b) == idx.end()) {
				idx[b] = ++m;
			}
			ed.PB(Edge(idx[a], idx[b], r, p, i + 1));
		}
		sort(ed.begin(), ed.end());
		for (int i = 1; i <= m; i++) fa[i] = i;
		LL res = 0;
		for (int i = 0; i < n; i++) {
			int pa = find(ed[i].a), pb = find(ed[i].b);
			if (pa != pb) {
				res += ed[i].p;
				fa[pa] = pb;
			}
		}
		cout << res << endl;
		for (int i = ed.size() - 1; i >= 0; i--) {
			printf("%d%c", ed[i].id, i == 0 ? '\n' : ' ');
		}
	}
	return 0;
}

void dp(){
	int i,j,k;
	for(i=0;i<cnt;i++)
	  for(j=0;j<=n/2;j++)
	    knap[i][j].tf=0;
	knap[0][0].tf=1;
	knap[0][0].pre=0;
	for(i=1;i<cnt;i++){
	  for(j=n/2;j>=0;j--){
	  	for(k=0;k<2;k++)
		  	if(j>=L[i].bg[k].size()&&knap[i-1][j-L[i].bg[k].size()].tf){
		  		knap[i][j].tf=1;
		  		knap[i][j].pre=j-L[i].bg[k].size();
		  		knap[i][j].op=k;
		  	}
	  }
	}
	int now;
	for(i=n/2;i>=0;i--)
	  if(knap[cnt-1][i].tf){
	  	now=i;
	  	break;
	  }
	for(i=cnt-1;i>=0;i--){
		int OP=knap[i][now].op;
		for(j=0;j<L[i].bg[OP].size();j++)
			A.PB(L[i].bg[OP][j]);
		now=knap[i][now].pre;
	}
}

void calc()
{
	pll pos = {0, 0};
	ll R = 2000000;

	while(R > 0)
	{
//		cout<<"R = "<<R<<" @ "<<pos<<endl;
		if(R > 3)
			R = ceill(sqrtl(R * R / 2.l));
		else
			R--;
		ll dR = max(R, 1LL);
//		cout<<"dR "<<dR<<endl;

		for(int i=0; i<4; i++)
		{
			pll newpos = trim(pos + dir[i] * dR);
			int res = query(newpos, R);
//			cout<<pos<<" -> "<<newpos<<" : "<<res<<endl;
			if(res > 0)
			{
				pos = newpos;
				break;
			}
		}
	}

	assert(query(pos, 0) > 0);
	vfound.PB(pos);
}

void traverse(int i,map<int,int >vec,map<int,bool>row,map<int,bool>col)
{
    if(vec.size()==8)
    {
        bool bt = true;
        for(int i =0; i<mymap.size(); i++)
        {
            if(mymap[i]==vec)
                bt =false;
        }
        if(bt)
            mymap.PB(vec);
    }
    else
    {
        if(i+1>7)
            i =0;
        else
            i++;
        for(int j =0; j<8; j++)
        {
            if(row.find(i) ==row.end() && col.find(j) ==col.end() && check(vec,i,j))
            {
                map<int,int>temp = vec;
                map<int,bool>t =row;
                map<int,bool>f= col;
                t[i] =true;
                f[j] = true;
                temp[j] =i;
                traverse(i,temp,t,f);
            }
        }
    }
}

int main(){
	ios_base::sync_with_stdio(false);
	cin >> n >> m;
	for(int i = 1; i <= n; i++){
		cin >> c[i];
		Min = min(Min, c[i]);
	}
	while(m--){
		int fi, se;
		cin >> fi >> se;
		if(c[fi] != c[se])
			e.PB(MP(min(c[fi], c[se]), max(c[fi], c[se])));
	}
	sort(e.begin(), e.end());
	e.resize(unique(e.begin(), e.end()) - e.begin());
	for(int i = 0; i < e.size(); i++)
		a[e[i].L]++, a[e[i].R]++;
	int Max = -1, ans;
	for(int i = 1; i <= 1e5; i++)
		if(a[i] > Max)
			Max = a[i], ans = i;
	if(Max == 0)
		cout << Min << endl;
	else
		cout << ans << endl;
	return 0;
}

int main()
{
    int g;
    scanf("%d", &g);
    for(int i=0; i<g; i++)
    {
        int a,b;
        scanf("%d %d", &a, &b);
        v.PB(MP(a,b));
    }
    int m;
    scanf("%d", &m);
    for(int i=0; i<m; i++)
    {
        int x,y,r;
        scanf("%d %d %d", &x, &y, &r);
        for(int xx=max(0,x-r); xx<min(MX,x+r+1); xx++)
        {
            for(int yy=max(0,y-r); yy<min(MX,y+r+1); yy++)
            {
                if((xx-x)*(xx-x) + (yy-y)*(yy-y) <= r*r)
                    A[xx][yy]=true;
            }
        }
    }
    int ans=0;
    for(int i=0; i<v.size(); i++)
    {
        if(!A[v[i].F][v[i].S])
            ans++;
    }
    printf("%d\n", ans);
    return 0;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	memset(v, -1, sizeof v);
	memset(vc, -1, sizeof vc);
	cin >> n >> m;
	while(m--){
		int fi, se, th;
		cin >> fi >> se >> th;
		v[fi] = th;
		vc[se] = fi;
	}
	for(int i = 1; i <= n; i++){
		if(v[i] != -1)
			continue;
		int zarf = 1e9;
		int x = i;
		while(vc[x] != -1){
			x = vc[x];
			zarf = min(zarf, v[x]);
		}
		if(x != i)
			ans.PB(MP(MP(x, i), zarf));
	}
	sort(ans.begin(), ans.end());
	cout << ans.size() << '\n';
	for(auto x : ans)
		cout << x.L.L << ' ' << x.L.R << ' ' << x.R << '\n';
	return 0;
}

void recurse(int val[8],bool arr[8],int t)
{
	if(t==8)
	{
	vector<int>x(8);
	for(int i =0;i<8;i++)
	x[i ] =val[i];
	if(search(x))
	{
		
		//cout<<endl;
		mymap.PB(x);
	}
	}
	else
	{
			for(int j =0;j<8;j++)
			{
				if(arr[j] == false && check(val,t,j))
				{
					val[t] = j;
					arr[j] =true;
					recurse(val,arr,t+1);
					arr[j] = false;
				}
			}
	}
}

int main()
{
	//freopen("test.in", "r", stdin);
	scanf("%d", &n);
	if(n == 2) { puts("2"); return 0; }
	for(int i = 0; i < n; i++)
		scanf("%d", &a[i]);
	for(int i = 0; i < n; i++)
		s.PB(a[i]);
	sort(s.BG, s.ED);
	int size = unique(s.BG, s.ED) - s.BG;
	for(int i = size; i < s.SZ; i++)
		s.erase(s.BG + i);
	for(int i = 0; i < s.SZ; i++)		
		f[i].clear();
	for(int i = 0; i < n; i++)
		f[lower_bound(s.BG, s.BG + size, a[i]) - s.BG].PB(i);
	for(int i = 0; i < size; i++) ans = max(ans, (int)f[i].SZ);
	for(int i = 0; i < size; i++)	
		for(int j = 0; j < size; j++)
		if(i != j)
		{
			ans = max(ans, cal(f[i], f[j]));
		}
	cout << ans << endl;
}

int bfs(bool visited[], queue<int> &que, int r, int c, int graph[]){
	int temp;
	int count = 0;
	int flag = 0;
	queue <int > output;
	int n = r * c;
	visited[que.front()] = 1;
	while(!que.empty()){
		temp = que.front();
		if(temp == n-1) flag = 1;
		//cout << "Front: " << temp << endl;
		if (temp % c && !visited[temp -1]){
			visited[temp - 1] = 1;que.push(temp - 1);
		}
		if(temp % c != c-1 && !visited[temp + 1]){
			visited[temp + 1] = 1;que.push(temp + 1);
		}
		if (temp / c && !visited[temp - c]){
			visited[temp - c] = 1;que.push(temp - c);
		}
		if(temp / c != r-1 && !visited[temp + c]){
			visited[temp + c] = 1;que.push(temp + c);
		}
		que.pop();
		// output.push(temp);
		count ++;
	}
	if(flag) mark = count;
	else conn_components.PB(count);
	return flag;
}

int main(int argc, char const *argv[])
{
	int Test;
	scanf("%d", &Test);
	while (Test--) {
		store.clear();
		E = 0;
		memset(last, -1, sizeof(last));
		scanf("%d%d", &n, &m);
		//for (int i = 0; i < n; i++) adj[i].clear();
		for (int i = 0; i < m; i++) {
			int a, b, c;
			scanf("%d%d%d", &a, &b, &c);
			addEdge(a, b, c);
			addEdge(b, a, c);
		}
		scanf("%d", &s);
		for (int i = 0; i < s; i++) {
			int x;
			scanf("%d", &x);
			store.PB(x);
			dijkstra(i);
		}
		dijkstra(s);
		solve();
	}
	return 0;
}

void input(void){
	LL inp;
	cin >> inp;
	while(inp)
		num.PB(inp % 10), inp /= 10;
	return;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> h >> w >> n;
    for(int i = 0; i < n; i++) {
        int fi, se;
        cin >> fi >> se;
        bl.PB(MP(fi, se));
    }
    sort(bl.begin(), bl.end());
    if(bl[0] == MP(1LL, 1LL) or bl.back() == MP(h, w)) {
        cout << 0 << endl;
        return 0;
    }
    fact[0] = 1;
    revfact[0] = 1;
    for(LL i = 1; i < 250000; i++) {
        fact[i] = (fact[i - 1] * i) % Mod;
        revfact[i] = ((get(fact[i], Mod).L % Mod) + Mod) % Mod;
    }
    for(int i = bl.size() - 1; i >= 0; i--) {
        dp[i] = C(h - bl[i].L + w - bl[i].R, h - bl[i].L);
        for(int j = i + 1; j < bl.size(); j++)
            dp[i] = (dp[i] - ((C(bl[j].L + bl[j].R - bl[i].L - bl[i].R, bl[j].L - bl[i].L) * dp[j]) % Mod)) % Mod;
        if(dp[i] < 0)
            dp[i] += Mod;
    }
    LL ans = C(h + w - 2, h - 1);
    for(int i = 0; i < bl.size(); i++)
        ans = (ans - ((C(bl[i].L + bl[i].R - 2, bl[i].L - 1) * dp[i]) % Mod)) % Mod;
    cout << (ans + Mod) % Mod << endl;
    return 0;
}

int main() {
	IOS;
	cin >> N >> M;
	for (int i=0, u, v; i<M; i++) {
		cin >> u >> v;
		E[v].PB(u);
		deg[u]++;
	}
	set<int> pq;
	for (int i=1; i<=N; i++) {
		if (!deg[i]) pq.insert(i);
	}
	while (!pq.empty()) {
		int u = *pq.rbegin();
		ans.PB(u);
		pq.erase(u);
		for (auto v : E[u]) {
			deg[v]--;
			if (!deg[v]) pq.insert(v);
		}
	}
	reverse(ALL(ans));
	for (int i=0; i<N; i++) {
		cout << ans[i] << " \n"[i==N-1];
	}

    return 0;
}