another 4 sorting and searching problems

CSES - CSES Problem Set/Sum_of_Two_Values.cpp

@@ -0,0 +1,33 @@
+//  Sum of Two Values
+
+#include<bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int main() {
+    map<ll, vector<int>> input;
+    int n; cin >> n;
+    ll x; cin >> x;
+    vector<ll> in;
+    for (int i{}; i < n; i++) {
+        ll a; cin >> a;
+        input[a].push_back(i);
+        in.push_back(a);
+    }
+    for (int i{}; i < n; i++) {
+        ll target = x - in[i];
+        bool flag = target == in[i];
+        if (input[target].empty() || (input[target].size() == 1 && flag)) continue;
+        else {
+            if (flag) {
+                cout << i + 1 << " " << input[target][1] + 1<< endl;
+            } else {
+                cout << i + 1 <<  " " << input[target][0] + 1<< endl;
+            }
+            return 0;
+        }
+    }
+    cout << "IMPOSSIBLE" << endl;
+    return 0;
+}