Задача этой книги дать краткое и четкое изложение языка С++ в соответствии со стандар том iso/iec 14882. Она предназначена для студентов, изучающих язык «с нуля»

next_permutation, prev_permutation

Ýëåìåíòû ëþáîé ïîñëåäîâaòåëüíîñòè ìîæíî ðañïîëîæèòü ðaçíûìè ñïîñîáaìè. Äëя ïîñëåäîâaòåëüíîñòè äëèíû n òaêèõ ïåðåñòaíîâîê ñóùåñòâóåò n! (1*2*…*n). Àëãîðèòì next_permutatiOn ïðîèçâîäèò î÷åðåäíóþ ïåðåñòaíîâêó â ëåêñèêîãðaôè-
÷åñêîì ïîðяäêå, a aëãîðèòì prev_permutatiOn — ïðåäûäóùóþ. Àëãîðèòìû âîçâða- ùaþò áóëåâñêîå çía÷åíèå true, åñëè ñëåäóþùaя ïåðåñòaíîâêa ñóùåñòâóåò, è false â ïðîòèâíîì ñëó÷aå.

template

bOOl next_permutatiOn(Bi first, Bi last); template
bOOl next_permutatiOn(Bi first, Bi last, COmpare COmp); template
bOOl prev_permutatiOn(Bi first, Bi last); template
bOOl prev_permutatiOn(Bi first, Bi last, COmpare COmp);
Ïðèìåð:
inClude inClude using namespaCe std; int main(){
COnst intm= 3;
int a[m]={1, 4, 2}, b[m]; int i;
COpy(a,a+ m, b);
COut << " next_permutatiOn(a, a + m):" << endl; while (next_permutatiOn(a, a + m)){
fOr (i= 0;i< m; i++) COut << a[i] << " "; COut << endl;}
COut << " prev_permutatiOn(b, b + m):" << endl; while (prev_permutatiOn(b, b + m)){
fOr (i= 0;i< m; i++) COut << b[i] << " "; COut << endl;}
return 0;
}
Ðåçóëüòaò ðaáîòû ïðîãðaììû:
next_permutatiOn(a,a+ m):
214
241
412
421
prev_permutatiOn(b,b+ m):
124

nth_element

Àëãîðèòì âûïîëíяåò ÷añòè÷íóþ ñîðòèðîâêó ìaññèâa. Ïîñëå âûïîëíåíèя aëãî- ðèòìa çía÷åíèå ýëåìåíòa, çaäaííîãî èòåðaòîðîì nth, áóäåò òaêèì æå, êaê ïîñëå ïîëíîé ñîðòèðîâêè, òî åñòü âñå ýëåìåíòû ëåâåå ýòîé ïîçèöèè áóäóò ìåíüøå íåãî, a âñå, ÷òî ïðaâåå, — áîëüøå.
template
vOid nth_element(Ran first, Ran nth, Ran last); template

vOid nth_element(Ran first, Ran nth, Ran last, COmpare COmp);

partial_ sort, partial_sort_copy

Àëãîðèòì partial_ sOrt òaêæå âûïîëíяåò ÷añòè÷íóþ ñîðòèðîâêó ïîñëåäîâaòåëü- íîñòè. Ïîñëå âûïîëíåíèя aëãîðèòìa ýëåìåíòû îò first äî middle áóäóò ðañïîëa- ãaòüñя â òaêîì æå ïîðяäêå, êaê ïîñëå ïîëíîé ñîðòèðîâêè.
Àëãîðèòì partial_sOrt_COpy âûïîëíяåò òå æå äåéñòâèя ñ êîïèåé ïîñëåäîâaòåëüíîñòè.
template
vOid partial_sOrt(Ran first, Ran middle, Ran last); template
vOid partial_sOrt(Ran first, Ran middle, Ran last, COmpare COmp);
template
Ran partial_sOrt_COpy(In first, In last, Ran result_first, Ran result_last);
template Ran partial_sOrt_COpy(In first, In last,
Ran result_first, Ran result_last, COmpare COmp);
×añòè÷íaя ñîðòèðîâêa ýêîíîìèò âðåìя â òåõ ñëó÷aяõ, êîãäa íañ èíòåðåñóþò òîëü- êî íåñêîëüêî ñaìûõ áîëüøèõ èëè ñaìûõ ìaëåíüêèõ çía÷åíèé, íaïðèìåð, «ãîðя-
÷aя äåñяòêa».
inClude inClude using namespaCe std; int main(){
COnst intm= 8;
int a[m] = {3, 1, 2, 34, 8, 7, 20, 2};
int i;