uva 10131 Is Bigger Smarter?（动态规划：LIS变形+路径打印）

#include <vector>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define MAXN 1010
using namespace std;

int dp[MAXN];
vector<int> vec;
struct Elepant {
int w, s, id;
}a[MAXN];

bool cmp(Elepant c, Elepant d) {
if(c.w < d.w) {
return true;
}
if(c.w == d.w)
return c.s > d.s;
return false;
}

void dfs(int pos) {
if(pos < 1) return ;
for(int i=pos-1; i>=0; --i) {
if(dp[pos] == dp[i]+1 && a[pos].w>a[i].w && a[pos].s<a[i].s) {
vec.push_back(a[i].id);
dfs(i);
break;
}
}
return ;
}

int main(void) {
int cnt = 0;
while(scanf("%d%d", &a[cnt].w, &a[cnt].s) != EOF) {
a[cnt].id = cnt+1;
++cnt;
}

a[cnt].id = cnt+1;
++cnt;

sort(a, a+cnt, cmp);

for(int i=0; i<cnt; ++i) {
dp[i] = 1;
}

for(int i=0; i<cnt; ++i) {
for(int j=i+1; j<cnt; ++j) {
if(a[j].w>a[i].w && a[j].s<a[i].s)
dp[j] = max(dp[j], dp[i]+1);
}
}
/*
for(int i=0; i<cnt; ++i)
printf("%d\t%d\t%d\n", a[i].w, a[i].s, dp[i]);
*/
int ans = -1;
int pos, res;
for(int i=0; i<cnt; ++i) {
if(ans <= dp[i]) {
ans = dp[i];
pos = i;
res = a[i].id;
}
}

printf("%d\n", ans);

vec.clear();
vec.push_back(res);
dfs(pos);
for(int i=vec.size()-1; i>=0; --i)
printf("%d\n", vec[i]);

return 0;
}