81 lines
2.5 KiB
C++
81 lines
2.5 KiB
C++
#include <stdio.h>
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#include <string.h>
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#define oo 100000
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bool dfs(int, int);
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int n,m,mini;
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bool finished[14];
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struct CLASS {
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char name[8];
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int time,preNum;
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int prerequisites[13];
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} subject[15];
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bool permit(int num) {
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int i;
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for(i=0; i<subject[num].preNum && finished[subject[num].prerequisites[i]]; i++);
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if(i == subject[num].preNum) return true;
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return false;
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}
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bool selectAndDfs(int total, int elect, int from, int que[], int result[], int lev, int semester) {
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int i;
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if(total-from < elect) return false;
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if(from == total && elect == 0) {
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for(i=0; i<m; i++) finished[result[i]] = true;
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dfs(lev+m, semester+1);
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for(i=0; i<m; i++) finished[result[i]] = false;
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return true;
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}
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for(i=from; i<total; i++) {
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result[m-elect] = que[i];
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selectAndDfs(total, elect-1, i+1, que, result, lev, semester);
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}
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return true;
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}
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bool dfs(int lev, int semester) {
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if(semester-1 >= mini) return false;
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if(lev == n) {
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if(semester-1 < mini) mini = semester-1;
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return true;
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}
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int i,tn=0,que[15];
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for(i=0; i<n; i++) if(!finished[i] && permit(i) && (subject[i].time & (1<<semester%2)) != 0) que[tn++] = i;
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if(tn <= m) {
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for(i=0; i<tn; i++) finished[que[i]] = true;
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dfs(lev+tn,semester+1);
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for(i=0; i<tn; i++) finished[que[i]] = false;
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}
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else {
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int temp[15];
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selectAndDfs(tn,m,0,que,temp,lev,semester);
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}
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return false;
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}
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int main() {
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while(scanf("%d%d", &n, &m) == 2 && !(n == -1 && m == -1)) {
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int i,j,k,p,t;
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for(i=0; i<n; i++) {
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scanf("%s", &subject[i].name);
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subject[i].time = subject[i].preNum = 0;
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}
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for(i=0; i<n; i++) {
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char s[10];
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scanf("%s", s);
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for(j=0; j<n && strcmp(s, subject[j].name) != 0; j++);
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scanf("%s", s);
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if(s[0] == 'B') subject[j].time = 3;
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else if(s[0] == 'S') subject[j].time = 1;
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else subject[j].time = 2;
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scanf("%d", &t);
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for(k=0; k<t; k++) {
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scanf("%s", s);
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for(p=0; p<n && strcmp(s, subject[p].name) != 0; p++);
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subject[j].prerequisites[subject[j].preNum++] = p;
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}
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}
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memset(finished, 0, sizeof(finished));
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mini = oo;
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dfs(0,1);
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printf("The minimum number of semesters required to graduate is %d.\n", mini);
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}
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return 0;
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}
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